Chapter 35 IS-IS - Arista Networks · Chapter 35: IS-IS IS-IS 2457 In scenarios when Border Gateway...

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Chapter 35

IS-ISIntermediate System-to-Intermediate System (IS-IS) intra-domain routing information exchangeprotocol is designed by the International Organization for Standardization to support connectionlessnetworking. This protocol is a dynamic routing protocol.

This chapter contains the following sections.

• Section 35.1: IS-IS Introduction

• Section 35.2: IS-IS

• Section 35.3: IS-IS Graceful Restart

• Section 35.4: IS-IS Commands

35.1 IS-IS IntroductionIS-IS is a link-state protocol, which uses the shortest path first (SPF) algorithm. IS-IS and the OSPFprotocol are similar in many aspects. As an interior gateway protocol (IGP), IS-IS runs inside an AS. Toenable IS-IS, you must instantiate an IS-IS routing instance and assign it to an interface.

35.2 IS-ISThese sections describe IS-IS configuration tasks:

• Section 35.2.1: Enabling IS-IS

• Section 35.2.2: IS-IS Optional Global Parameters

• Section 35.2.3: IS-IS Interface Optional Parameters

• Section 35.2.4: Disabling IS-IS

• Section 35.2.5: Verifying IS-IS

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IS-IS Chapter 35: IS-IS

35.2.1 Enabling IS-IS

For the normal operation of the IS-IS protocol, the router isis command must be used to enable theIS-IS instance. Then the net command is used to set a Network Entity Title (NET) for the device. Next,you must configure at least one address-family. Lastly, the isis enable command is used to enable IS-ISon the desired interface. The IS-IS protocol is enabled upon the completion of these configurations.

To enable IS-IS, the following tasks must be performed.

• Section 35.2.1.1: Enable IS-IS Globally and Specify an IS-IS Instance

• Section 35.2.1.2: Configure the Network Entity Title (NET)

• Section 35.2.1.3: Set the Address Family Configuration

• Section 35.2.1.4: Enable IS-IS on a Specified Interface

35.2.1.1 Enable IS-IS Globally and Specify an IS-IS Instance

The switch supports only one IS-IS routing instance per VRF. The routing instance uniquely identifiesthe switch to other devices. IS-IS configuration commands apply globally to the IS-IS instance.

The switch must be in router IS-IS configuration mode to run IS-IS configuration commands. The routerisis command places the switch in router IS-IS configuration mode.

Example

• These commands place the switch in IS-IS configuration mode. It also creates an IS-IS routinginstance named Osiris.

switch(config)#router isis Osirisswitch(config-router-isis)#

35.2.1.2 Configure the Network Entity Title (NET)

After creating an IS-IS routing instance, you should also configure the Network Entity Title (NET) withthe net command. The NET defines the current IS-IS area address and the system ID of the device.

Example

• These commands define the current IS-IS area address and the system ID of the device.

switch(config)#router isis Osirisswitch(config-router-isis)# net 49.0001.1010.1040.1030.00

35.2.1.3 Set the Address Family Configuration

The address-family command allows you to enable the address families that IS-IS will route and alsoenter a configuration sub-mode to configure settings that are distinct to that address family. Theaddress families supported are IPv4 unicast and IPv6 unicast.

Example

• These commands enable and enter the address family mode for IPv4 unicast.

switch(config)#router isis Osirisswitch(config-router-isis)#address-family ipv4 unicast switch(config-router-isis-af)#

Chapter 35: IS-IS IS-IS

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35.2.1.4 Enable IS-IS on a Specified Interface

After enabling IS-IS, you need to specify on which interface IS-IS will be run with the isis enablecommand.

Example

• These commands enable IS-IS on the specified interface Ethernet 4.

switch(config-router-isis)#interface ethernet 4switch(config-if-Eth4)#isis enable Osiris

35.2.2 IS-IS Optional Global Parameters

After globally enabling IS-IS, the following global parameters can be configured.

• Section 35.2.2.1: Set the Router Type

• Section 35.2.2.2: Configuring Redistribution of Connected or Static non-ISIS Routes

• Section 35.2.2.3: Configuring Redistribution of Connected or Static non-ISIS Routes into Level-1

• Section 35.2.2.4: Configuring Redistribution of BGP Routes into ISIS Network

• Section 35.2.2.5: Set the Overload Bit

• Section 35.2.2.6: Configure IS-IS MD5 Authentication

• Section 35.2.2.7: Set the SPF Interval

• Section 35.2.2.8: Configuring IS-IS Segment Routing Global Adjacency-SID

• Section 35.2.2.9: Enable Logging for Peer Changes

• Section 35.2.2.10: Set the IS-IS hostname

• Section 35.2.2.11: Configuring IS-IS Multi-Topology

35.2.2.1 Set the Router Type

The is-type command sets the routing level for an IS-IS instance.

Example

• These commands specify level-2 for the IS-IS instance.

switch(config)#router isis Osirisswitch(config-router-isis)#is-type level-2switch(config-router-isis)#

35.2.2.2 Configuring Redistribution of Connected or Static non-ISIS Routes

The redistribute (IS-IS) command configures redistribution of connected or static non-ISIS routes.

Example

• These commands redistribute connected routes into the IS-IS domain.

switch(config)#router isis Osirisswitch(config-router-isis)#redistribute connectedswitch(config-router-isis)#

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35.2.2.3 Configuring Redistribution of Connected or Static non-ISIS Routes into Level-1

The non-ISIS routes can be exported into Level-1, Level-2 or both by using route map’s set condition.By default, the routes are exported only to Level-2. The Level-1 or Level-2 routes can also be filteredusing the route map’s match statement. The route map is then used when redistributing routes in ISIS.

The following example shows the steps to configure route redistribution into Level-1 or Level-2:

Example

Step 1 Place the switch in route-map mode and use set isis level command to configure a route mapto set the IS-IS level.

Switch(config-route-map-rm)#set isis level [level-1|level-2|level-1-2]

Step 2 The configured route map is then used while redistributing routes in ISIS using the redistribute(IS-IS) command.

Switch(config-router-isis)#redistribute [connected|static] route-map <route-map name>

Output of show isis database detail is used to make sure that the route shows up in the exportedlevel.

35.2.2.4 Configuring Redistribution of BGP Routes into ISIS Network

The redistribute bgp route-map command advertises the routes learned through BGP routes into theIS-IS network. It also allows the user to selectively advertise some routes and modify route attributesbefore advertising using route-maps.

The command is available in both address-family mode and router IS-IS mode, however, the commandis rejected if configured in both address-family mode and router mode at the same time.

Note If the command is configured in router address family mode, it only redistributes routes with matchingaddress family. If it is configured in router mode, it applies to all enabled address-families.

Use show isis database detail command to verify that routes are advertised with correct attributes.

Examples

• In this example the redistribute bgp route-map command redistributes the BGP routes into ISISdomain, in address-family mode.

Switch(config)#router isis 1Switch(config-router-isis)#address-family ipv4Switch(config-router-isis-af)#redistribute bgp route-map bgp-to-isis-v4

• In this example the redistribute bgp route-map command redistributes the BGP routes into ISIS,in router isis mode.

Switch(config)#router isis 1Switch(config-router-isis)#redistribute bgp route-map bgp-to-isis

35.2.2.5 Set the Overload Bit

The set-overload-bit command used without the on-startup option, informs other devices not to use thelocal router to forward transit traffic. When used with the on-startup option, the overload bit is set forthe interval specified after startup.


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In scenarios when Border Gateway Protocol (BGP) routes are resolved using an Interior GatewayProtocol (IGP), if the transit router reboots and becomes available again, the IGP will consider thetransit router as an optimal path again. After rebooting, the transit router will blackhole traffic until thetransit router learns the external destination reachability information via BGP.

Examples

These commands configure the switch and sets the overload bit to 120 seconds after startup.

switch(config)#router isis Osirisswitch(config-router-isis)#set-overload-bit on-startup 120 switch(config-router-isis)#

• These commands configure the overload bit until BGP converges. If BGP fails to converge withinthe set timeout default period, then the overload bit gets cleared.

switch(config)#router isis Osirisswitch(config-router-isis)#set-overload-bit on-startup wait-for-bgpswitch(config-router-isis)#set-overload-bit on-startup wait-for-bgp timeout 750switch(config-router-isis)#

35.2.2.6 Configure IS-IS MD5 Authentication

To configure authentication for the IS-IS instance causing LSPs, CSNPs and PSNPs to beauthenticated, use the authentication mode and authentication key commands. To configureauthentication on the interface, causing IS-IS Hellos to be authenticated, use the isis authenticationmode. and isis authentication key commands on the interface.

Two forms of authentication are supported by the IS-IS routing protocol: Clear-text authentication andMD5 authentication. The difference between the two forms of authentication is in the level of securityprovided. In the case of clear-text authentication, the password is specified as text in the authenticationTLV, making it possible for an attacker to break authentication by sniffing and capturing IS-IS PDUs onthe network. Arista recommends using the MD5 authentication.

HMAC MD5 authentication provides much stronger authentication by computing the message digest(on the IS-IS PDU contents) using the secret key to produce a hashed message authentication code(HMAC). Different modes of authentication can be specified on the interface, which authenticates IIHPDUs (IS-IS hello PDUs), and globally in the router IS-IS mode, in which the LSPs, CSNPs and PSNPsare authenticated. Area-wide and domain-wide authentication can be specified for L1 and L2 routersrespectively.

Example

• These commands configure authentication for the IS-IS instance causing LSPs, CSNPs andPSNPs to be authenticated.

switch(config)#router isis 1switch(config-router-isis)#authentication mode md5switch(config-router-isis)#authentication key secretswitch(config-router-isis)#

• These commands configure authentication on the interface causing IS-IS Hellos to beauthenticated.

switch(config)#interface Ethernet 3/6switch(config-if-Et3/6)#isis authentication mode textswitch(config-if-Et3/6)#isis authentication key 7 cAm28+9a/xPi04o7hjd8Jw==switch(config-if-Et3/6)#

To maximize interoperability, Arista recommends using the same key in both interface mode and inrouter isis mode.

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35.2.2.7 Set the SPF Interval

The SPF timer interval defines the maximum interval between two successive SPF calculations. IS-ISruns SPF calculations following a change in the network topology or the link-state database. Thespf-interval command defines the following intervals:

• Maximum wait interval: The maximum time a switch will wait before running an SPF after atopology change.

• Initial wait interval: In a network that has been stable throughout the hold interval, this intervaldefines the initial wait time of a switch for performing an SPF calculation after a topology change.As several link-state updates must be sent after a topology change, the initial wait interval allowsthe network to settle before a switch computes an SPF. If the topology changes during an initialwait interval, an SPF is calculated after the initial wait interval expires and no further changes aremade to throttle timers.

• Hold time: This interval delays SPF calculations during network instability. If the topology changesduring a hold time, an SPF is computed when the hold time expires. Subsequent hold intervals aredoubled up to the configured maximum wait interval for continuous topology changes. If the nexttopology change occurs after the hold interval expires, the hold interval is reset to its configuredvalue and the SPF is computed after the initial wait interval.

Note EOS does not support configuring topology-specific SPF timers in multi-topology deployments andIS-IS level-specific SPF timers.

Example

This command configures maximum wait interval, initial wait interval, and hold time to 10 seconds,2000 ms, and 1000 ms respectively.

switch(config)#router isis inst1switch(config-router-isis)#spf-interval 10 2000 1000

35.2.2.8 Configuring IS-IS Segment Routing Global Adjacency-SID

IS-IS Segment Routing (SR) now supports global adjacency SIDs for point-to-point interfaces. Theadjacency SID is configured as an index using the adjacency-segment command.

Global adjacency segments are represented using an index instead of actual MPLS labels. The indexis an offset into the Segment Routing Global Block (SRGB) advertised by a router, resulting in an MPLSlabel. The default value of SRGB in EOS is Base: 900000 and Size: 65536.

The same index may be used to configure multiple interfaces so that MPLS forms an ECMP group, andthe same index may be applied to IPv4 and IPv6 adjacencies.

Example

• In this example, the global adjacency is configured on a point-to-point interface Ethernet Et1, withan index value 10.

Arista(config-if-Et1)#adjacency-segment ipv4 p2p index 10 global

Displaying Adjacency SID Information

The command show isis segment-routing adjacency-segments displays the global adjacency SIDvalue and other related information.


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Examples

• In this example an interface is configured as follows:

interface Ethernet1 ip address 1.1.1.1/24 ipv6 address 1000::1/64 isis enable isis1 isis network point-to-point adjacency-segment ipv4 p2p index 1 global adjacency-segment ipv6 p2p index 2 global

• The show output for the above interface configuration:

Switch# show isis segment-routing adjacency-segments

System ID: 1000.0000.0002 Instance: isis1SR supported Data-plane: MPLS SR Router ID: 1.1.1.4Adj-SID allocation mode: SR-adjacenciesAdj-SID allocation pool: Base: 100000 Size: 16384Adjacency Segment Count: 2Flag Descriptions: F: Ipv6 address family, B: Backup, V: Value L: Local, S: Set

Segment Status codes: L1 - Level-1 adjacency, L2 - Level-2 adjacency, P2P - Point-to-Point adjacency, LAN - Broadcast adjacency

Locally Originated Adjacency SegmentsAdj IP Address Local Intf SID SID Source Flags Type ---------------- ---------- ------ ------------- --------------- ------- 1.1.1.2 Et1 1 Configured F:0 B:0 V:0 L:0 S:0 P2P L1fe80::1:ff:fe65:0 Et1 2 Configured F:1 B:0 V:0 L:0 S:0 P2P L1

Received Global Adjacency Segments SID Originator Neighbor Flags --------- -------------------- ---------------- --------- 0 rtrmpls1 1000.0000.0002 F:0 B:0 V:0 L:0 S:0

35.2.2.9 Enable Logging for Peer Changes

The log-adjacency-changes (IS-IS) command configures the switch to send syslog messages when itdetects IS-IS neighbor adjacency state changes.

Example

• These commands configure the switch to send a syslog message when a neighbor goes up ordown.

switch(config)#router isis Osirisswitch(config-router-isis)#log-adjacency-changesswitch(config-router-isis)#

35.2.2.10 Set the IS-IS hostname

The is-hostname command configures the use of a human-readable string to represent the symbolicname of an IS-IS router. It also changes the output of IS-IS show commands, to show the IS-IShostname in place of system IDs if the corresponding IS-IS hostname is known. However, syslogs stilluse IS-IS system IDs and not the IS-IS hostname.

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By default if there’s a hostname configured on the switch, it is used as the IS-IS hostname. It is alsopossible to un-configure an assigned hostname for IS-IS using the no is-hostname command. Whenthe IS-IS hostname is removed, the switch goes back to using the switch’s hostname as the IS-IShostname.

Examples

• These commands configure the IS-IS hostname to the symbolic name “ishost1” for the IS-IS router.

switch(config)#router isis inst1switch(config-router-isis)#is-hostname ishost1switch(config-router-isis)#

• These commands unconfigure the IS-IS hostname of the symbolic name “ishost1” for the IS-ISrouter.

switch(config)#router isis inst1switch(config-router-isis)#no is-hostname ishost1switch(config-router-isis)#

35.2.2.11 Configuring IS-IS Multi-Topology

The multi-topology command configures IS-IS Multi-Topology (MT) support (disabled by default),enabling an IS-IS router to compute a separate topology for IPv4 and IPv6 links in the network. WithMT configured, not all the links in a network need to support both IPv4 and IPv6. Some can supportIPv4 or IPv6 individually. The IPv4 SPF will install IPv4 routes using the IPv4 topology, and similarly,the IPv6 SPF will install IPv6 routes using the IPv6 topology. Without MT support, all links in an IS-ISnetwork need to support the same set of address families.

When MT is enabled, and each link has a separate IPv4 metric and IPv6 metric.

The isis ipv6 metric command configures the IPv6 metric.

The isis multi-topology command configures the IPv4 or IPv6 address family individually on an interfacewith both IPv4 and IPv6 addresses.

The address families that are enabled on an interface are based on the global address families enabledin router IS-IS configuration mode, and the addresses configured on the interface. To enable aparticular address family on an interface, it needs to have an address configured in that address family.In the case where both IPv4 and IPv6 address families are enabled in router IS-IS configuration mode,then if an interface has IPv4 and IPv6 addresses, both IPv4 and IPv6 address families are enabled onthat interface. In the case of an interface with only an IPv4 address family, the IPv4 address family isenabled on that interface. Where an interface only has an IPv6 address family, the IPv6 address familyis enabled on that interface. Finally, where only the IPv6 address family is enabled in router IS-IS configmode and MT is enabled, then the IPv6 address family is enabled on all interfaces which have an IPv6address configured.

Examples

• These commands configure MT for the IS-IS router.

switch(config)#router isis 1switch(config-router-isis)#address-family ipv6 unicastswitch(config-router-isis-af)#multi-topologyswitch(config-router-isis-af)#

• These commands unconfigure MT for the IS-IS router.

switch(config)#router isis 1switch(config-router-isis)#address-family ipv6 unicastswitch(config-router-isis-af)#no multi-topologyswitch(config-router-isis-af)#


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• These commands configure the IPv6 metric.

switch(config)#interface Ethernet 5/6switch(config-if-Et5/6)#isis ipv6 metric 30switch(config-if-Et5/6)#

• These commands configure the IPv4 address family on an interface with both IPv4 and IPv6addresses.

switch(config)#interface Ethernet1switch(config-if-Et1)#isis multi-topology address-family ipv4 unicastswitch(config-if-Et1)#


switch(config)#interface Ethernet1switch(config-if-Et1)#isis multi-topology address-family ipv6 unicastswitch(config-if-Et1)#

• These commands configure both the IPv4 and IPv6 address families on an interface.

switch(config)#interface Ethernet1switch(config-if-Et1)#no isis multi-topology address-family unicastswitch(config-if-Et1)#

35.2.3 IS-IS Interface Optional Parameters

After globally enabling IS-IS, the following parameters can be configured on individual interfaces.

• Section 35.2.3.1: Set the Hello Packet Interval

• Section 35.2.3.2: Configure the Hello Multiplier for the Interface

• Section 35.2.3.3: Configure the IS-IS Metric

• Section 35.2.3.4: Set the LSP Transmission Interval

• Section 35.2.3.5: Set the IS-IS Priority

• Section 35.2.3.6: Configure an Interface as Passive

• Section 35.2.3.7: Configure BFD support for IS-IS for IPv4

35.2.3.1 Set the Hello Packet Interval

The isis hello-interval command sets the time interval between the hello packets that maintain an IS-ISadjacency.

Example

• These commands configure a hello interval of 60 seconds for Ethernet 4.

switch(config)#interface ethernet 4switch(config-if-Et4)#isis hello-interval 60 switch(config-if-Et4)#

35.2.3.2 Configure the Hello Multiplier for the Interface

The switch maintains the adjacency by sending/receiving hello packets. When receiving no hellopackets from the peer within a time interval, the local switch considers the neighbors invalid.

The isis hello-multiplier command calculates the hold time announced in hello packets by multiplyingthis number with the configured isis hello-interval.

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Example

• These commands configure a hello multiplier of 5 for Ethernet 4.

switch(config)#interface ethernet 4switch(config-if-Et4)#isis hello-interval 60switch(config-if-Et4)#isis hello-multiplier 5switch(config-if-Et4)#

35.2.3.3 Configure the IS-IS Metric

The isis metric command sets the cost for sending information over a specific interface. At present onlywide metrics are supported.

Example

• These commands configure a metric cost of 30 for sending information over Ethernet 5.

switch(config)#interface ethernet 5switch(config-if-Et5)#isis metric 30switch(config-if-Et5)#

35.2.3.4 Set the LSP Transmission Interval

The isis lsp tx interval command configures the minimum interval between successive LSPtransmissions on an interface.

Example

• This command sets the LSP transmission interval on interface Ethernet 5 to 50 milliseconds.

switch(config)#interface ethernet 5switch(config-if-Et5)# isis lsp tx interval 50switch(config-if-Et5)#

35.2.3.5 Set the IS-IS Priority

The isis priority command determines which device will be the Designated Intermediate System (DIS).The device with the highest priority on the LAN will become the DIS.

Example

• These commands configure a device priority of 60 on interface Ethernet 5.

switch(config)#interface ethernet 5switch(config-if-Et5)#isis priority 60switch(config-if-Et5)#

35.2.3.6 Configure an Interface as Passive

The isis passive and passive (IS-IS) commands configure IS-IS interfaces as passive to interfaceswhere adjacencies are wanted. The interface does not send or receive IS-IS packets when configuredas passive.

Examples

• These commands configure Ethernet interface 10 as a passive interface.

switch(config)#interface ethernet 10switch(config-if-Etl0)#isis passiveswitch(config-if-Etl0)#


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• These commands configure Ethernet interface 10 as a passive interface in the router IS-IS mode.

switch(config)#router isis Osirisswitch(config-router-isis)#passive interface ethernet 10switch(config-router-isis)#

35.2.3.7 Configure BFD support for IS-IS for IPv4

The isis bfd and bfd all-interfaces commands configure Bidirectional Forwarding Detection (BFD). BFDis supported for both IS-IS IPv4 and IPv6 routes.

Examples

• These commands enable BFD (for the IPv4 address family) for all the interfaces on which IS-IS isenabled. By default, BFD is disabled on all interfaces.

switch(config)#router isis 1switch(config-router-isis)#address-family ipv4switch(config-router-af)#bfd all-interfacesswitch(config-router-af)#

• These commands enable BFD on an IS-IS interface.

switch(config)#interface Ethernet 5/6switch(config-if-Et5/6)#isis bfdswitch(config-if-Et5/6)#

35.2.4 Disabling IS-IS

An IS-IS instance can be shut down globally or can be disabled on individual interfaces.

The shutdown (IS-IS) command shuts down an IS-IS instance globally.

Example

• These commands disable IS-IS globally without modifying the IS-IS configuration.

switch(config)#router isis Osirisswitch(config-router-isis)#shutdownswitch(config-router-isis)#

The no isis enable command disables IS-IS on an interface.

Example

• These commands disable IS-IS on interface Ethernet 4.

switch(config-router-isis)#interface ethernet 4switch(config-if-Eth4)#no isis enable

35.2.5 Verifying IS-IS

The following tasks verify the IS-IS peer and connection configuration:

• Section 35.2.5.1: Verify the Link State Database

• Section 35.2.5.2: Verify the Interface Information for the IS-IS Instance

• Section 35.2.5.3: Verify the IS-IS Neighbor Information

• Section 35.2.5.4: Verify IS-IS Instance Information

Bidirectional%20Forwarding%20Detection.pdf

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35.2.5.1 Verify the Link State Database

To display the link state database of IS-IS, use the show isis database command.

Example

• This command displays the IS-IS link state database.

switch>show isis database

ISIS Instance: Osiris ISIS Level 2 Link State Database LSPID Seq Num Cksum Life IS Flags 1212.1212.1212.00-00 4 714 1064 L2 <> 1212.1212.1212.0a-00 1 57417 1064 L2 <> 2222.2222.2222.00-00 6 15323 1116 L2 <> 2727.2727.2727.00-00 10 15596 1050 L2 <> 3030.3030.3030.00-00 12 62023 1104 L2 <> 3030.3030.3030.c7-00 4 53510 1104 L2 <>switch>

35.2.5.2 Verify the Interface Information for the IS-IS Instance

To display interface information related to the IS-IS instance, use the show isis interface command.

Example

• This command displays IS-IS interface information.

switch>show isis interface

ISIS Instance: Osiris Interface Vlan20: Index: 59 SNPA: 0:1c:73:c:5:7f MTU: 1497 Type: broadcast Level 2: Metric: 10, Number of adjacencies: 2 LAN-ID: 1212.1212.1212, Priority: 64 DIS: 1212.1212.1212, DIS Priority: 64 Interface Ethernet30: Index: 36 SNPA: 0:1c:73:c:5:7f MTU: 1497 Type: broadcast Level 2: Metric: 10, Number of adjacencies: 1 LAN-ID: 3030.3030.3030, Priority: 64 DIS: 3030.3030.3030, DIS Priority: 64switch>

35.2.5.3 Verify the IS-IS Neighbor Information

To display general information for IS-IS neighbors that the device sees, use show isis neighbors.


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Example

• This command displays information for IS-IS neighbors that the device sees.

switch>show isis neighbor

Inst Id System Id Type Interface SNPA State Hold time10 2222.2222.2222 L2 Vlan20 2:1:0:c:0:0 UP 3010 1212.1212.1212 L2 Vlan20 2:1:0:d:0:0 UP 910 3030.3030.3030 L2 Ethernet30 2:1:0:b:0:0 UP 9switch>

35.2.5.4 Verify IS-IS Instance Information

To display the system ID, Type, Interface, IP address, State and Hold information for IS-IS instances,use the show isis summary command. The command is also used to verify the configured maximumwait interval, initial wait interval, and hold time of SPF timers in IS-IS instances. This command alsodisplays values of the current SPF interval, last level-1 SPF run, and last level-2 SPF run.

Example

• This command displays general information about IS-IS instances.

switch>show isis summaryISIS Instance: Osiris System ID: 1010.1040.1030, administratively enabled, attached Internal Preference: Level 1: 115, Level 2: 115 External Preference: Level 1: 115, Level 2: 115 IS-Type: Level 2, Number active interfaces: 1 Routes IPv4 only Last Level 2 SPF run 2:32 minutes ago Area Addresses: 10.0001 level 2: number dis interfaces: 1, LSDB size: 1switch>

• This command displays the SPF interval information about IS-IS instances.

switch(config-router-isis-af)#show isis summary

IS-IS Instance: 1 VRF: default System ID: 0000.0000.0001, administratively enabled Multi Topology disabled, not attached IPv4 Preference: Level 1: 115, Level 2: 115 IPv6 Preference: Level 1: 115, Level 2: 115 IS-Type: Level 1 and 2, Number active interfaces: 0 Routes both IPv4 and IPv6 Max wait(s) Initial wait(ms) Hold interval(ms) LSP Generation Interval: 5 50 50 SPF Interval: 2 1000 1000 Current SPF hold interval(ms): Level 1: 1000, Level 2: 1000 Last Level 1 SPF run 1 seconds ago Last Level 2 SPF run 1 seconds ago Authentication mode: Level 1: None, Level 2: None Graceful Restart: Disabled, Graceful Restart Helper: Enabled Area Addresses: 49.0001 level 1: number dis interfaces: 0, LSDB size: 1 level 2: number dis interfaces: 0, LSDB size: 1

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IS-IS Graceful Restart Chapter 35: IS-IS

35.3 IS-IS Graceful RestartIS-IS Graceful Restart (GR) is a mechanism to prevent routing protocol re-convergence during aprocessor switchover or device downtime. Normally, when a router restarts, all the neighboring routersassociated with that router detect the device has gone down and routes from that neighbor areremoved. Upon the restart of the router, the session is re-established and data transfer continues.During the restart, the removal and re-insertion of routes will result in data loss. This can be preventedby configuring graceful restart on the device.

When IS-IS is used as the interior gateway protocol (IGP), the following EOS features require nonstopforwarding (NSF) and support for the graceful restart from IS-IS:

• ASU2 – Software upgrades.

• SSO – Planned SSO initiated by an operator for maintenance or Unplanned SSO due to failureson the active supervisor.

• RIB agent restart due to software failures.

With IS-IS Graceful Restart (GR) configured, a redundancy switchover from active to standbysupervisor, or ASU2, or restart of the IS-IS software (the RIB Agent) should be a hitless event if the GRcompletes successfully. Neighboring routers will continue to forward traffic to the restarting router andtraffic forwarding through the restarting router continues without loss. If GR is successful, the failure ofa router should be completely transparent to network applications.

ISIS Graceful Restart (GR) is compatible with the following platforms:

• IS-IS GR with unplanned software restart is supported on all platforms.

• IS-IS GR with SSO is supported on modular dual-supervisor platforms.

• IS-IS GR with ASU2 is supported on platforms that support ASU2.

35.3.1 Configuring IS-IS Graceful Restart (GR)

By default, IS-IS graceful restart is disabled. Use the graceful-restart command to configure gracefulrestart on an IS-IS router. By default IS-IS graceful-restart-helper functionality is enabled, and todisable it use no graceful-restart-helper command.

Examples

• In this example IS-IS graceful restart is configured with t2 wait time of 30 seconds for level-1 routes.

switch(config)# router isis 1switch(config-router-isis)# graceful-restart t2 level-1 30

t2 is the maximum wait time for the LSP database to synchronize (SPF computation is not done whilet2 is running). t2 can be configured for either level-1 or level-2 through the CLI. The default value is 30seconds, and the allowed configuration range is 5 to 300 seconds.

• In this example an ISIS graceful restart is configured with restart-hold-time of 50 seconds.

switch(config)# router isis 1switch(config-router-isis)# graceful-restart restart-hold-time 50

In case of a planned restart, the hold time advertised by the IS-IS router prior to restart should begreater than the time for which the router is expected to be offline. Otherwise, neighboring routers willbring down the adjacency before the restarting router has a chance to send a restart request in its hellopacket, which may result in traffic loss.

In case of ASU2, the IS-IS router instance will advertise a hello hold time of <restart-hold-time> onthose interfaces for which the configured hold time is less than restart-hold-time. This is done justbefore the router restarts.

Chapter 35: IS-IS IS-IS Graceful Restart

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Note Once the router has restarted, the router’s advertised hello hold time will depend on the “hello-interval”and “hello-multiplier” configuration on each interface as before. By default, the restart-hold-time isdisabled.

Important! For Graceful Restart to be successful, the hold time advertised by the router should be greater thanthe time it takes for Graceful Restart to complete. If the restarting router is DIS, hold time advertised is1/3rd of the configured value (default is 9s). We recommend increasing the hold time for the DIS to ahigher value before a planned restart; otherwise, it may result in traffic loss.

35.3.2 Displaying IS-IS Graceful Restart (GR) Information

GR State can be one of the following:

• Last Start/Restart was completed successfully.

• Last Start/Restart exited after t2 (level-1/level-2) expiry.

• Last Restart exited after t3 expiry.

• Start/Restart in progress.

• Graceful Restart was disabled during startup.

The following show commands are used to display the IS-IS graceful restart information.

• The show isis graceful-restart vrf [vrf-name] command displays the GR configuration andgraceful-restart related state of the IS-IS instance as well as its neighbors.

Example

switch#show isis graceful-restart vrf defaultIS-IS Instance: 1 VRF: default System ID: 0000.0000.0001 Graceful Restart: Enabled, Graceful Restart Helper: Enabled State: Last Start exited after T2 (level-1) expiry T1 : 3s T2 (level-1) : 30s/20s remaining T2 (level-2) : 30s/not running T3 : not running

System ID Type Interface Restart Capable Statusis-hostname-1 L1L2 Ethernet1 Yes Runningis-hostname-2 L1 Ethernet2 Yes Restarting

• The show isis summary vrf [vrf-name] command displays the graceful restart state and helperconfiguration.

Example

switch#show isis summary vrf defaultIS-IS Instance: 1 VRF: default System ID: 0000.0000.0001, administratively enabled .... Graceful Restart: Enabled, Graceful Restart Helper: Enabled

• The show isis neighbors detail vrf [vrf-name] command displays the helper’s view of a restartingrouter.

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IS-IS Graceful Restart Chapter 35: IS-IS

Example

switch#show isis neighbors detail vrf defaultInstance VRF System Id Type Interface SNPA State Hold time Circuit Id1 default OT1 L1 Ethernet1 2:1:0:b4:0:0 UP 29839 OT3.05 Area Address(es): 49.0001 SNPA: 2:1:0:b4:0:0 .... Graceful Restart: Supported, Status: Restarting (RR rcvd, RA sent, CSNP sent)

• The show isis interface detail vrf [vrf-name] command displays the graceful restart related statsfor that interface.

Example

switch#show isis interface detail vrf defaultISIS Instance: ISISQ VRF: default Interface Ethernet1: Index: 2 SNPA: P2P ... Level 1:

Graceful Restart Status: RR sent, SA sent, RA rcvd, CSNP rcvd

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35.4 IS-IS CommandsGlobal Configuration Commands• clear isis neighbor• router isis

Interface Configuration Commands• adjacency-segment• authentication key• authentication mode• bfd all-interfaces• isis authentication key• isis authentication mode• isis bfd• isis enable• isis hello-interval• isis hello-multiplier• isis ipv6 metric• isis lsp tx interval• isis metric• isis multi-topology• isis network• isis passive• isis priority

Router IS-IS Configuration Mode (Includes Address-Family Mode)• address-family• graceful-restart (IS-IS)• is-hostname• is-type• log-adjacency-changes (IS-IS)• match isis level• multi-topology• net• passive (IS-IS)• redistribute (IS-IS)• set isis level• set-overload-bit• shutdown (IS-IS)• spf-interval

Display Commands – EXEC Mode• show isis database• show isis graceful-restart vrf• show isis hostname• show isis interface• show isis neighbors• show isis network topology• show isis segment-routing adjacency-segments• show isis summary

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IS-IS Commands Chapter 35: IS-IS

address-family

The address-family command places the switch in address-family configuration mode.

Address-family configuration mode is not a group change mode; running-config is changedimmediately after commands are executed. The exit command does not affect the configuration.

The switch supports these address families:

• ipv4-unicast

• ipv6-unicast

The no address-family and default address-family commands delete the specified address-familyfrom running-config by removing all commands previously configured in the correspondingaddress-family mode.

The exit command returns the switch to IS-IS configuration mode.

Command ModeRouter-IS-IS Configuration

Command SyntaxADDRESS_FAMILY [ipv4 | ipv6] [MODE]no ADDRESS_FAMILY [ipv4 | ipv6]default ADDRESS_FAMILY [ipv4 | ipv6]

Parameters• ADDRESS_FAMILY Options include:

• ipv4 IPv4 unicast

• ipv6 IPv6 unicast

• MODE Options include:

• <no parameter> Defaults to unicast.

• unicast All IPv4 or IPv6 addresses are active.

Example• These commands enter the address family mode for IPv4 unicast.

switch(config)#router isis Osirisswitch(config-router-isis)#address-family ipv4 unicast switch(config-router-isis-af)#

• To exit from the IPv4 IS-IS unicast address family configuration mode, enter the followingcommand.

switch(config)#router isis Osirisswitch(config-router-isis)#address-family ipv4 unicast switch(config-router-isis-af)#exitswitch(config-router-isis)#


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adjacency-segment

The adjacency-segment command configures the local or global adjacency-SID for a point-to-pointinterface for IS-IS adjacencies.

The no adjacency-segment and default adjacency-segment commands restore the switch to itsdefault state by removing the corresponding adjacency-segment command from running-config.

Command ModeInterface Configuration

Command Syntaxadjacency-segment <ipv4|ipv6> p2p <index|label> globalno adjacency-segment <ipv4|ipv6> p2p <index|label> globaldefault adjacency-segment <ipv4|ipv6> p2p <index|label> global

Parameters• ipv4 IS-IS SR adjacency segment IPv4 interface configuration.

• ipv6 IS-IS SR adjacency segment IPv6 interface configuration.

• index Index to be assigned as Adj-SID for adjacency on this interface. The value ranges from 0to 65535.

• label Label value to be assigned as Adj-SID for adjacency on this interface. The value rangesfrom 16 to 1048575.

• global global adjacency SID.

Example• In this example, the global adjacency is configured on a point-to-point interface Ethernet Et1, with

an index value 10.

Switch(config-if-Et1)#adjacency-segment ipv4 p2p index 10 global

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authentication key

The authentication key command configures the authentication key for the IS-IS instance causingLSPs, CSNPs and PSNPs to be authenticated.

The no authentication key and default authentication key commands disables the authenticationkey for the IS-IS instance.

Command ModeISIS-Router Configuration

Command Syntaxauthentication key [0 | 7] [LAYER_VALUE]no authentication key [0 | 7] [LAYER_VALUE]default authentication key [0 | 7] [LAYER_VALUE]

Parameters• LAYER_VALUE layer value; options include:

• level-1

• level-2

Examples• These commands configure authentication for the IS-IS instance causing LSPs, CSNPs and

PSNPs to be authenticated.

switch(config)#router isis 1switch(config-router-isis)#authentication key secretswitch(config-router-isis)#


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authentication mode

The authentication mode command configures authentication for the IS-IS instance causing LSPs,CSNPs and PSNPs to be authenticated.

The no authentication mode and default authentication mode commands disables authenticationfor the IS-IS instance.

Command ModeISIS-Router Configuration

Command Syntaxauthentication mode <md5 | text> [LAYER_VALUE]no authentication mode <md5 | text> [LAYER_VALUE]default authentication mode <md5 | text> [LAYER_VALUE]


• level-1

• level-2

Examples• These commands configure authentication for the IS-IS instance causing LSPs, CSNPs and

PSNPs to be authenticated.

switch(config)#router isis 1switch(config-router-isis)#authentication mode md5switch(config-router-isis)#

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bfd all-interfaces

The bfd all-interfaces command enables Bidirectional Forwarding Detection (BFD) for allIS-IS-enabled interfaces in the IPv4 or IPv6 address family.

Use the isis bfd command to configure BFD on a specific interface.

Command ModeRouter-Address-Family Configuration

Command Syntaxbfd all-interfaces

Example• These commands enable BFD for all the interfaces on which IS-IS is enabled. By default, BFD is

disabled on all the interfaces.

switch(config)#router isis 1switch(config-router-isis)#address-family ipv4switch(config-router-af)#bfd all-interfacesswitch(config-router-af)#


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clear isis neighbor

The clear isis neighbor command clears IS-IS adjacencies that exist on an interface, or at a specificlevel, or the adjacencies formed with a given neighbor (either with a system ID or a hostname).

Command ModePrivileged EXEC

Command Syntaxclear isis neighbor {Neighbor-ID | all | interface} [level-1 | level-2 | level-1-2]

Parameters• Neighbor-ID clears adjacencies based on the system ID or the hostname of a neighbor.

• all clears all adjacencies.

• interface clears adjacencies for a specific interface.

• level-1 level 1 only.

• level-1-2 level 1-2 point-to-point only.

• level-2 level 2 only.

Examples• This command clears IS-IS adjacencies with a neighbor af86.3032.1a0f.

switch#clear isis neighbor af86.3032.1a0f2 neighbors cleared on instance 1switch#

• This command clears all IS-IS adjacencies on an interface et1.

switch#clear isis neighbor interface et14 neighbors cleared on instance 1switch#

• This command clears IS-IS adjacencies with a neighbor af86.3032.1a0f and on interface et1.

switch#clear isis neighbor af86.3032.1a0f interface et12 neighbors cleared on instance 1switch#

• This command clears all IS-IS adjacencies at Level 1 and on interface et1.

switch#clear isis neighbor interface et1 level-12 neighbors cleared on instance 1switch#

• This command clears Level 1-2 point-to-point adjacencies only.

switch#clear isis neighbor all level-1-20 neighbors cleared on instance 1switch#

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graceful-restart (IS-IS)

The graceful-restart command configures IS-IS graceful-restart. The command provides options toconfigure the t2 time or the restart-hold-time.

t2 is the maximum wait time for the LSP database to synchronize (SPF computation is not done whilet2 is running). t2 can be configured for either level-1 or level-2 routes.

restart-hold-time is the hold time advertised by the router to its neighbors before undergoing ASU2fast reboot.

The no graceful-restart and default graceful-restart commands disables the IS-IS graceful-restartconfiguration from running-config.


Command Syntaxgraceful-restart <t2 | restart-hold-time> <value>no graceful-restart <t2 | restart-hold-time> <value>default graceful-restart <t2 | restart-hold-time> <value>

Parameters• value The time in seconds. Value ranges from 5 to 300 seconds.

• restart-hold-time Sets the hold time when restarting.

• t2 Sets the LSP database sync wait time. Options include.

Examples• In this example an ISIS graceful restart is configured with t2 wait time of 30 seconds for level-1

routes.

switch(config)# router isis 1switch(config-router-isis)# graceful-restart t2 level-1 30

• In this example an ISIS graceful restart is configured with restart-hold-time of 50 seconds.

switch(config)# router isis 1switch(config-router-isis)# graceful-restart restart-hold-time 50


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is-hostname

The is-hostname command configures the use of a human-readable string to represent the symbolicname of an IS-IS router. It also changes the output of IS-IS show commands, to show the IS-IShostname in place of system IDs if the corresponding IS-IS hostname is known. However, syslogs stilluse IS-IS system IDs and not the IS-IS hostname.

By default, if a hostname is configured on the switch, it is used as the IS-IS hostname. It is also possibleto unconfigure an assigned hostname for IS-IS using the no is-hostname command. When the IS-IShostname is removed, the switch goes back to using the switch’s hostname as the IS-IS hostname.


Command Syntaxis-hostname <string>no is-hostname

Example• These commands configure the IS-IS hostname to the symbolic name ishost1 for the IS-IS router.

switch(config)#router isis inst1switch(config-router-isis)#is-hostname ishost1switch(config-router-isis)#

• These commands unconfigure the IS-IS hostname of the symbolic name ishost1 for the IS-ISrouter.

switch(config)#router isis inst1switch(config-router-isis)#no is-hostname ishost1switch(config-router-isis)#

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is-type

The is-type command configures the routing level for an IS-IS instance.

An IS-IS router can be configured as Level-1-2 which can form adjacencies and exchange routinginformation with both Level-1 and Level-2 routers. A Level-1-2 router can be configured to transferrouting information from Level-1 to Level-2 areas and vice versa (via route leaking). By default, allroutes from Level-1 area are always leaked into Level-2 network.


Command Syntaxis-type LAYER_VALUE

Parameters• LAYER_VALUE layer value options include:

• level-1

• level-1-2

• level-2

Example• These commands configure Level 1-2 routing.

switch(config)#router isis Osirisswitch(config-router-isis)#is-type level-1-2switch(config-router-isis)#

• These commands configure Level 2 routing.

switch(config)#router isis Osirisswitch(config-router-isis)#is-type level-2switch(config-router-isis)#


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isis authentication key

The isis authentication key command configures the authentication key on the interface causingIS-IS Hellos to be authenticated.

The no isis authentication mode and default isis authentication mode commands disables theauthentication key for the IS-IS instance.

Command ModeInterface-Ethernet Configuration

Command Syntaxisis authentication key [0 | 7] [LAYER_VALUE]no isis authentication key [0 | 7] [LAYER_VALUE]default isis authentication key [0 | 7] [LAYER_VALUE]


• level-1

• level-2

Examples• These commands configure authentication on the interface causing IS-IS Hellos to be

authenticated.


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isis authentication mode

The isis authentication mode command configures authentication on the interface causing IS-ISHellos to be authenticated.

The no isis authentication mode and default isis authentication mode commands disablesauthentication for the IS-IS instance.


Command Syntaxisis authentication mode <md5 | text> [LAYER_VALUE]no isis authentication mode <md5 | text> [LAYER_VALUE]default isis authentication mode <md5 | text> [LAYER_VALUE]


• level-1

• level-2

Examples• These commands configure authentication on the interface causing IS-IS Hellos to be

authenticated.



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isis bfd

The isis bfd command activates the corresponding IS-IS routing instance on the configuration modeinterface. By default, the IS-IS routing instance is not enabled on an interface.

The no isis enable and default isis enable commands disable IS-IS on the configuration modeinterface by removing the corresponding isis enable command from running-config.


Command Syntaxisis bfdno isis bfddefault isis bfd

Examples• These commands enable BFD on IS-IS interfaces.

switch(config)#interface Ethernet 5/6switch(config-if-Et5/6)#isis bfdswitch(config-if-Et5/6)#

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isis enable

The isis enable command activates the corresponding IS-IS routing instance on the configurationmode interface. By default, the IS-IS routing instance is not enabled on an interface.

The no isis enable and default isis enable commands disable IS-IS on the configuration modeinterface by removing the corresponding isis enable command from running-config.

Command ModeInterface-Ethernet ConfigurationInterface-Loopback ConfigurationInterface-Port-channel ConfigurationInterface-VLAN Configuration

Command Syntaxisis enable instance_idno isis enabledefault isis enable

Parameters• instance_id IS-IS instance name.

Examples• These commands enable the IS-IS protocol on the interface Ethernet 4.

switch(config)#router isis Osirisswitch(config-router-isis)# net 49.0001.1010.1040.1030.00switch(config-router-isis)#interface ethernet 4switch(config-if-Eth4)#isis enable Osiris

• These commands disable the IS-IS protocol on the interface Ethernet 4.

switch(config)#interface ethernet 4switch(config-if-Eth4)# no isis enable


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isis hello-interval

The isis hello-interval command sends Hello packets from applicable interfaces to maintain theadjacency through the transmitting and receiving of Hello packets. The Hello packet interval can bemodified.

The no isis hello-interval and default isis hello-interval commands restore the default hello intervalof 10 seconds on the configuration mode interface by removing the isis hello-interval command fromrunning-config.


Command Syntaxisis hello-interval timeno isis hello-intervaldefault isis hello-interval

Parameters• time Values range from 1 to 300; default is 10.

Examples• These commands configure a hello interval of 45 seconds for VLAN 200.

switch(config)#interface vlan 200switch(config-if-Vl200)#isis hello-interval 45 switch(config-if-Vl200)#

• These commands remove the configured hello interval of 45 seconds from VLAN 200.

switch(config)#interface vlan 200switch(config-if-Vl200)#no isis hello-intervalswitch(config-if-Vl200)#

• These commands configure a hello interval of 60 seconds for Ethernet 5.

switch(config)#interface ethernet 5 switch(config-if-Et5)#isis hello-interval 60 switch(config-if-Et5)#

• These commands remove the configured hello interval of 60 seconds from Ethernet 5.

switch(config)#interface ethernet 5 switch(config-if-Et5)#no isis hello-interval switch(config-if-Et5)#

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isis hello-multiplier

The isis hello-multiplier command specifies the number of IS-IS hello packets missed by a neighborbefore the the adjacency is considered down.

The no isis hello-multiplier and default isis hello-multiplier commands restore the default hellointerval of 3 on the configuration mode interface by removing the isis hello-multiplier command fromrunning-config.


Command Syntaxisis hello-multiplier factorno isis hello-multiplierdefault isis hello-multiplier

Parameters• factor Values range from 3 to 100; default is 3

Examples• These commands configure a hello multiplier of 4 for VLAN 200.

switch(config)#interface vlan 200switch(config-if-Vl200)#isis hello-multiplier 4switch(config-if-Vl200)#

• These commands remove the configured hello multiplier of 4 from VLAN 200.

switch(config)#interface vlan 200switch(config-if-Vl200)# no isis hello-multiplier switch(config-if-Vl200)#

• These commands configure a hello multiplier of 45 for Ethernet 5.

switch(config)#interface ethernet 5switch(config-if-Et5)#isis hello-multiplier 45switch(config-if-Et5)#

• These commands remove the configured hello multiplier of 45 from Ethernet 5.

switch(config)#interface ethernet 5switch(config-if-Et5)#no isis hello-multiplier switch(config-if-Et5)#


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isis ipv6 metric

The isis ipv6 metric command configures the IPv6 metric.

The no isis ipv6 metric and default isis ipv6 metric commands restore the default metric of 10 onthe configuration mode interface.


Command Syntaxisis ipv6 metric metric_valueno isis ipv6 metricdefault isis ipv6 metric

Parameters• metric_value Values range from 1 to 16777214; default is 10.

Examples• These commands configure the IPv6 metric.

switch(config)#interface Ethernet 5/6switch(config-if-Et5/6)#isis ipv6 metric 30switch(config-if-Et5/6)#

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isis lsp tx interval

The isis lsp tx interval command sets the interval at which IS-IS sends link-state information on theinterface.

The no isis lsp tx interval and default isis lsp tx interval commands restores the default setting of33 ms. by removing the isis lsp tx interval command from running-config.


Command Syntaxisis lsp tx interval periodno isis lsp tx intervaldefault isis lsp tx interval

Parameters• period Value ranges from 1 through 3000. Default interval is 33 ms.

Examples• This command sets the LSP interval on interface Ethernet 5 to 600 milliseconds.

switch(config)#interface ethernet 5switch(config-if-Et5)# isis lsp tx interval 600switch(config-if-Et5)#

• This command removes the LSP interval on interface Ethernet 5.

switch(config)#interface ethernet 5switch(config-if-Et5)# no isis lsp tx intervalswitch(config-if-Et5)#


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isis metric

The isis metric command sets cost for sending information over an interface.

The no isis metric and default isis metric commands restore the metric to its default value of 10 byremoving the isis metric command from running-config.


Command Syntaxisis metric metric_costno isis metricdefault isis metric

Parameters• metric_cost Values range from 1 to 1677214. Default value is 10.

Examples• These commands configure a metric cost of 30 for sending information over Ethernet 5.

switch(config)#router isis Osirisswitch(config-router-isis)#interface ethernet 5switch(config-if-Et5)#isis metric 30switch(config-if-Et5)#

• These commands remove the configured metric cost of 30 from Ethernet 5.

switch(config)#router isis Osirisswitch(config-router-isis)#interface ethernet 5switch(config-if-Et5)#no isis metricswitch(config-if-Et5)#

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isis multi-topology

The isis multi-topology command configures the IPv4 or IPv6 address family individually on aninterface with both IPv4 and IPv6 addresses.

The no isis multi-topology and default isis multi-topology commands restores the default interfaceto both IPv4 and IPv6 address families.


Command Syntaxisis multi-topology address-family ipv4 unicastno isis multi-topology address-family ipv4 unicastdefault isis multi-topology address-family ipv4 unicast

Examples• These commands configure the IPv4 address family on an interface with both IPv4 and IPv6

addresses.

switch(config)#interface Ethernet 5/6switch(config-if-Et5/6)#isis multi-topology address-family ipv4 unicastswitch(config-if-Et5/6)#


switch(config)#interface Ethernet 5/6switch(config-if-Et5/6)#isis multi-topology address-family ipv6 unicastswitch(config-if-Et5/6)#

• These commands configure both the IPv4 and IPv6 address families on an interface.

switch(config)#interface Ethernet 5/6switch(config-if-Et5/6)#no isis multi-topology address-family unicastswitch(config-if-Et5/6)#


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isis network

The isis network command sets the configuration mode interface as a point-to-point link. By default,interfaces are configured as broadcast links.

The no isis network and default isis network commands set the configuration mode interface as abroadcast link by removing the corresponding isis network command from running-config.

Command ModeInterface-Ethernet ConfigurationInterface-Loopback ConfigurationInterface-Port-Channel ConfigurationInterface-VLAN Configuration

Command Syntaxisis network point-to-pointno isis networkdefault isis network

Examples• These commands configure Ethernet interface 10 as a point-to-point link.

switch(config)#interface ethernet 10switch(config-if-Etl0)# isis network point-to-pointswitch(config-if-Etl0)#

• This command restores Ethernet interface 10 as a broadcast link.

switch(config-if-Etl0)#no isis networkswitch(config-if-Etl0)#

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isis passive

The isis passive command disables IS-IS on an interface configured as passive. The switch won’tsend or process IS-IS packets received on passive interfaces. The switch will continue to advertise theIP address in the LSP.

The no isis passive command enables IS-IS on the interface. The default isis passive command setsthe interface to the default interface activity setting by removing the corresponding isis passive or noisis passive statement from running-config.

Command ModeInterface-Ethernet ConfigurationInterface-Loopback ConfigurationInterface-Port-Channel ConfigurationInterface-VLAN Configuration

Command Syntaxisis passiveno isis passivedefault isis passive

Examples• These commands configure Ethernet interface 10 as a passive interface.

switch(config)#router isis Osirisswitch(config-router-isis)#interface ethernet 10switch(config-if-Etl0)# isis passiveswitch(config-if-Etl0)#

• This command enables IS-IS on Ethernet interface 10.

switch(config-if-Etl0)#no isis passiveswitch(config-if-Etl0)#


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isis priority

The isis priority command sets the IS-IS priority for the interface.

The default priority is 64. The network device with the highest priority will be elected as the designatedintermediate router to send link-state advertisements for that network.

The no isis priority and default isis priority commands restore the default priority (64) on theconfiguration mode interface.


Command Syntaxisis priority priority_levelno isis prioritydefault isis priority

Parameters• priority_level Value ranges from 0 to 127. Default value is 64.

Examples• These commands configure a IS-IS priority of 60 on interface Ethernet 5.

switch(config)#router isis Osirisswitch(config-router-isis)#interface ethernet 5switch(config-if-Et5)#isis priority 60switch(config-if-Et5)#

• These commands restores the default IS-IS priority of 64 from interface Ethernet 5.

switch(config)#router isis Osirisswitch(config-router-isis)#interface ethernet 5switch(config-if-Et5)# no isis priority switch(config-if-Et5)#

• These commands configure the switch with a priority of 64 for VLAN 7.

switch(config)#interface vlan 7switch(config-if-Vl7)#isis priority 64switch(config-if-Vl7)#

• These command restores the default IS-IS priority of 64 for VLAN 7.

switch(config)#interface vlan 7switch(config-if-Vl7)#no isis priorityswitch(config-if-Vl7)#

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log-adjacency-changes (IS-IS)

The log-adjacency-changes command sets the switch to send syslog messages when it detects linkstate changes or when it detects that a neighbor state has changed.

The default option is active when running-config does not contain any form of the command. Enteringthe command in any form replaces the previous command state in running-config.


Command Syntaxlog-adjacency-changesno log-adjacency-changesdefault log-adjacency-changes

Examples• These commands configure the switch to send a syslog message when a neighbor state changes.

switch(config)#router isis Osirisswitch(config-router-isis)#log-adjacency-changesswitch(config-router-isis)#

• These commands configure not to log the peer changes.

switch(config)#router isis Osirisswitch(config-router-isis)#no log-adjacency-changesswitch(config-router-isis)#


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match isis level

The match isis level command configures a route map to match on ISIS level. It filters the Level-1 orLevel-2 routes by using route map’s match statement.

The no match isis level and default match isis level commands disables the match ISIS levelconfiguration from running-config.

Command ModeRoute-map Configuration

Command Syntaxmatch isis level [level-1|level-2]no match isis level [level-1|level-2]default set isis level [level-1|level-2]

Parameters• level-1 IS-IS level 1

• level-2 IS-IS level 2

Example• These commands place the switch in route-map mode, and configures a route map to match isis

level to level-1.

switch(config)#route-map Testswitch(config-route-map-test)# match isis level level-1

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multi-topology

The multi-topology command configures IS-IS Multi-Topology (MT) support (disabled by default),enabling an IS-IS router to compute a separate topology for IPv4 and IPv6 links in the network. WithMT configured, not all the links in a network need to support both IPv4 and IPv6. Some can supportIPv4 or IPv6 individually. The IPv4 SPF will install IPv4 routes using the IPv4 topology, and similarlythe IPv6 SPF will install IPv6 routes using the IPv6 topology. Without MT support, all links in an IS-ISnetwork need to support the same set of address families. When MT is enabled, and each link has aseparate IPv4 metric and IPv6 metric.

The no multi-topology and default multi-topology commands restores the default interface to bothIPv4 and IPv6 address families.

Command ModeRouter IS-IS Address Family Configuration

Command Syntaxmulti-topologyno multi-topologydefault multi-topology

Examples• These commands configure MT for the IS-IS router.

switch(config)#router isis 1switch(config-router-isis)#address-family ipv6 unicastswitch(config-router-isis-af)#multi-topologyswitch(config-router-isis-af)#

• These commands unconfigure MT for the IS-IS router.

switch(config)#router isis 1switch(config-router-isis)#address-family ipv6 unicastswitch(config-router-isis-af)#no multi-topologyswitch(config-router-isis-af)#


2495

net

The net command configures the Network Entity Title of the IS-IS instance. By default, no NET isdefined.

The no net and default net commands removes the NET from running-config.


Command Syntaxnet mask_hexno netdefault net

Parameters• maxk_hex mask value. Format is hh.hhhh.hhhh.hhhh.hhhh.hhhh.hhhh.hhhh.hhhh.hhhh.00.

Examples• These commands specify the NET as 49.0001.1010.1040.1030.00, in which the system ID is

1010.1040.1030, area ID is 49.0001.

switch(config)#router isis Osirisswitch(config-router-isis)# net 49.0001.1010.1040.1030.00switch(config-router-isis)#

• These commands remove NET 49.0001.1010.1040.1030.00 from running-config.

switch(config)#router isis Osirisswitch(config-router-isis)# no net 49.0001.1010.1040.1030.00switch(config-router-isis)#

2496


passive (IS-IS)

The passive command disables IS-IS on a passive interface. The switch will continue to advertise theIP address in the LSP.

The no passive command enables IS-IS on the interface. The default passive command sets theinterface to the default interface activity setting by removing the corresponding passive or no passivestatement from running-config.


Command Syntaxpassive INTERFACE_NAMEno passive INTERFACE_NAMEdefault passive INTERFACE_NAME

Parameters• INTERFACE_NAME Options include:

• ethernet e_range Ethernet interface list.

• loopback l_range Loopback interface list.

• port-channel p_range Channel group interface list.

• vlan v_range VLAN interface list.

Valid e_range, l_range, p_range, and v_range formats include number, range, or comma-delimitedlist of numbers and ranges.

Examples• These commands configure Ethernet interface 10 as a passive interface.

switch(config)#router isis Osirisswitch(config-router-isis)# passive interface ethernet 10

• This command restores Ethernet interface 10 as an active interface.

switch(config-if-Etl0)#no passiveswitch(config-if-Etl0)#


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redistribute (IS-IS)

The redistribute command redistributes the specified types of routes into IS-IS.

The no redistribute and default redistribute commands disable route redistribution from thespecified domain by removing the corresponding redistribute statement from running-config.


Command Syntaxredistribute ROUTE_TYPEno redistribute ROUTE_TYPEdefault redistribute ROUTE_TYPE

Parameters• ROUTE_TYPE The route type for which routes are redistributed. These are the option to

include.

• bgp Redistribution of BGP routes.

• connected Redistribution of connected routes.

• ospf Redistribution of OSPF routes.

• ospfv3 Redistribution of OSPFv3 routes.

• static Redistribution of static routes.

Examples• These commands redistribute connected routes into the IS-IS domain.

switch(config)#router isis Testswitch(config-router-isis)#redistribute connected

• These commands redistribute static routes into the IS-IS domain.

switch(config)#router isis Testswitch(config-router-isis)#redistribute static

• These commands redistribute the BGP routes into ISIS domain in address-family mode.

Switch(config)#router isis 1Switch(config-router-isis)#address-family ipv4Switch(config-router-isis-af)#redistribute bgp route-map bgp-to-isis-v4

• These commands redistribute the BGP routes into ISIS domain in router-isis mode.

Switch(config)#router isis 1Switch(config-router-isis)#redistribute bgp route-map bgp-to-isis

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router isis

The router isis command places the switch in router ISIS configuration mode.

Router ISIS configuration mode is not a group change mode; running-config is changed immediatelyafter commands are executed. The exit command does not affect the configuration.

The no router isis command deletes the IS-IS instance.

The exit command returns the switch to global configuration mode.

Command ModeGlobal Configuration

Command Syntaxrouter isis instance_name [VRF_INSTANCE]no router isis instance_namedefault router isis instance_name

Parameters• instance_name routing instance.

• VRF_INSTANCE

• <no parameter>

• vrf vrf_name

Examples• These commands places the switch in router IS-IS mode and creates an IS-IS routing instance

named Osiris.

switch(config)#router isis Osirisswitch(config-router-isis)#

• This command attempts to open an instance with a different routing instance name from that of theexisting instance. The switch displays an error and stays in global configuration mode.

switch(config)#router isis Osiris% More than 1 ISIS instance is not supportedswitch(config)#

• This command deletes the IS-IS instance.

switch(config)#no router isis Osirisswitch(config)#


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set isis level

The set isis level command configures a route map to set ISIS level.

The no set isis level and default set isis level commands disables the set ISIS level configurationfrom running-config.

Command ModeRoute-map Configuration

Command Syntaxset isis level [level-1|level-2|level-1-2]no set isis level [level-1|level-2|level-1-2]default set isis level [level-1|level-2|level-1-2]

Parameters• level-1 IS-IS level 1

• level-2 IS-IS level 2

• level-1-2 IS-IS level 1 and level 2

Example• These commands place the switch in route-map mode, and configures a route map to set isis level

to level-1.

switch(config)#route-map Testswitch(config-route-map-test)# set isis level level-1

2500


set-overload-bit

The set-overload-bit command used without the on-startup option will inform other devices not to usethis switch in SPF computation. When used with the on-startup parameter, the overload bit is set forthe interval after startup.

The no set-overload-bit and default set-overload-bit commands removes the correspondingset-overload-bit command from running-config.


Command Syntaxset-overload-bit TIMINGno set-overload-bitdefault set-overload-bit

Parameters• TIMING Options include:

• <no parameter>

• on-startup <1 to 3600>

Example• These commands configure the switch to sets the overload bit to 120 seconds after

startup.

switch(config)#router isis Osirisswitch(config-router-isis)#set-overload-bit on-startup 120 switch(config-router-isis)#

• These commands remove the configured overload bit of 120 seconds from the running-config.

switch(config)#router isis Osirisswitch(config-router-isis)#no set-overload-bit on-startup switch(config-router-isis)#


2501

show isis database

The show isis database command displays the link state database of IS-IS. The default commanddisplays active routes and learned routes.

Command ModeEXEC

Command Syntaxshow isis database [INSTANCES] [INFO_LEVEL]show isis database [INFO_LEVEL] VRF_INSTANCE

Parameters• INSTANCES Options include:

• <no parameter>

• instance_name

• INFO_LEVEL Options include:

• <no parameter>

• detail

• VRF_INSTANCE specifies the VRF instance.

• <no parameter>

• vrf vrf_name

Display Values• ISIS Instance

• LSPID

• Seq Num

• Cksum

• Life

• IS

Examples• This command displays general information about the link state database of IS-IS.

switch>show isis database

ISIS Instance: Osiris ISIS Level 2 Link State Database LSPID Seq Num Cksum Life IS Flags 1212.1212.1212.00-00 4 714 1064 L2 <> 1212.1212.1212.0a-00 1 57417 1064 L2 <> 2222.2222.2222.00-00 6 15323 1116 L2 <> 2727.2727.2727.00-00 10 15596 1050 L2 <> 3030.3030.3030.00-00 12 62023 1104 L2 <> 3030.3030.3030.c7-00 4 53510 1104 L2 <>switch>

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• This command displays detailed information about the link state database of IS-IS.

switch>show isis database detail

ISIS Instance: Osiris ISIS Level 2 Link State Database LSPID Seq Num Cksum Life IS Flags 1212.1212.1212.00-00 4 714 1060 L2 <> Area address: 49.0001 Interface address: 10.1.1.2 Interface address: 2002::2 IS Neighbor: 1212.1212.1212.0a Metric: 10 Reachability: 10.1.1.0/24 Metric: 10 Type: 1 Reachability: 2002::/64 Metric: 10 Type: 1 1212.1212.1212.0a-00 1 57417 1060 L2 <> IS Neighbor: 2727.2727.2727.00 Metric: 0 IS Neighbor: 2222.2222.2222.00 Metric: 0 IS Neighbor: 1212.1212.1212.00 Metric: 0 2222.2222.2222.00-00 6 15323 1112 L2 <> Area address: 49.0001 Interface address: 10.1.1.1 Interface address: 10.1.1.3 Interface address: 2002::3 IS Neighbor: 1212.1212.1212.0a Metric: 10 Reachability: 10.1.1.0/24 Metric: 10 Type: 1 Reachability: 10.1.1.0/24 Metric: 10 Type: 1 Reachability: 2002::/64 Metric: 10 Type: 1 2727.2727.2727.00-00 10 15596 1046 L2 <> Area address: 49.0001 Interface address: 10.1.1.1 Interface address: 30.1.1.1 Interface address: 2002::1 Interface address: 2001::1 IS Neighbor: 1212.1212.1212.0a Metric: 10 IS Neighbor: 3030.3030.3030.c7 Metric: 10 Reachability: 10.1.1.0/24 Metric: 10 Type: 1 Reachability: 30.1.1.0/24 Metric: 10 Type: 1 Reachability: 2002::/64 Metric: 10 Type: 1 Reachability: 2001::/64 Metric: 10 Type: 1 3030.3030.3030.00-00 12 62023 1100 L2 <> Area address: 49.0001 Interface address: 30.1.1.2 Interface address: 2001::2 IS Neighbor: 3030.3030.3030.c7 Metric: 10 Reachability: 12.1.1.0/24 Metric: 1 Type: 1 Reachability: 110.1.1.0/24 Metric: 0 Type: 1 Reachability: 30.1.1.0/24 Metric: 10 Type: 1 Reachability: 2001::/64 Metric: 10 Type: 1 3030.3030.3030.c7-00 4 53510 1100 L2 <> IS Neighbor: 2727.2727.2727.00 Metric: 0 IS Neighbor: 3030.3030.3030.00 Metric: 0switch>


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show isis graceful-restart vrf

The show isis graceful-restart vrf command displays the GR configuration and graceful-restartrelated state of the IS-IS instance as well as its neighbors.

Command ModeEXEC

Command Syntaxshow isis graceful-restart vrf <vrf-name>

Example

• In this example the show isis graceful-restart command displays the output for the default vrfinstance.

switch#show isis graceful-restart vrf defaultIS-IS Instance: 1 VRF: default System ID: 0000.0000.0001 Graceful Restart: Enabled, Graceful Restart Helper: Enabled State: Last Start exited after T2 (level-1) expiry T1 : 3s T2 (level-1) : 30s/20s remaining T2 (level-2) : 30s/not running T3 : not running

System ID Type Interface Restart Capable Statusis-hostname-1 L1L2 Ethernet1 Yes Runningis-hostname-2 L1 Ethernet2 Yes Restarting

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show isis hostname

The show isis hostname command displays mapping between the System ID and IS-IS hostname.

Command ModeEXEC

Command Syntaxshow isis hostname

Examples• This command mapping between the System ID and IS-IS hostnames host1 and host2.

switch>show isis hostnameISIS Instance: 1 VRF: defaultLevel System ID HostnameL1 1111.1111.1001 host1L1 1111.1111.1002 host2


2505

show isis interface

The show isis interface command displays interface information for the IS-IS instance.

Command ModeEXEC

Command Syntaxshow isis interface [INSTANCES] [INTERFACE_NAME] [INFO_LEVEL]show isis interface [INTERFACE_NAME] [INFO_LEVEL] VRF_INSTANCE


• <no parameter>

• instance_name

• INTERFACE_NAME Values include

• <no parameter> all interfaces.

• ethernet e_num Ethernet interface specified by e_num.

• loopback l_num Loopback interface specified by l_num.

• management m_num Management interface specified by m_num.

• port-channel p_num Port channel interface specified by p_num.

• vlan v_num VLAN interface specified by v_num.

• vxlan vx_num VXLAN interface specified by vx_num.


• <no parameter>

• detail


• <no parameter>

• vrf vrf_name

Display Values• ISIS Instance

• System ID

• Index

• MTU

• Metric

• LAN-ID

• DIS

• Type

• Interface

• SNPA

• State

• Hold time

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Examples• This command displays general IS-IS information for instance Osiris.

switch>show isis interface

ISIS Instance: Osiris Interface Vlan20: Index: 59 SNPA: 0:1c:73:c:5:7f MTU: 1497 Type: broadcast Level 2: Metric: 10, Number of adjacencies: 2 LAN-ID: 1212.1212.1212, Priority: 64 DIS: 1212.1212.1212, DIS Priority: 64 Interface Ethernet30: Index: 36 SNPA: 0:1c:73:c:5:7f MTU: 1497 Type: broadcast Level 2: Metric: 10, Number of adjacencies: 1 LAN-ID: 3030.3030.3030, Priority: 64

DIS: 3030.3030.3030, DIS Priority: 64


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• This command displays detailed IS-IS information for instance Osiris.

switch>show isis interface detail

ISIS Instance: Osiris Interface Vlan20: Index: 59 SNPA: 0:1c:73:c:5:7f MTU: 1497 Type: broadcast Level 2: Metric: 10, Number of adjacencies: 2 LAN-ID: 1212.1212.1212, Priority: 64 DIS: 1212.1212.1212, DIS Priority: 64 Adjacency 2222.2222.2222: State: UP, Level: 2 Type: Level 2 IS Hold Time: 30, Supported Protocols: ipv4, ipv6 SNPA: 2:1:0:c:0:0, Priority: 64 IPv4 Interface Address: 10.1.1.3 IPv6 Interface Address: fe80::1:ff:fe0c:0 Areas: 49.0001 Adjacency 1212.1212.1212: State: UP, Level: 2 Type: Level 2 IS Hold Time: 9, Supported Protocols: ipv4, ipv6 SNPA: 2:1:0:d:0:0, Priority: 64 IPv4 Interface Address: 10.1.1.2 IPv6 Interface Address: fe80::1:ff:fe0d:0 Areas: 49.0001 Interface Ethernet30: Index: 36 SNPA: 0:1c:73:c:5:7f MTU: 1497 Type: broadcast Level 2: Metric: 10, Number of adjacencies: 1 LAN-ID: 3030.3030.3030, Priority: 64 DIS: 3030.3030.3030, DIS Priority: 64 Adjacency 3030.3030.3030: State: UP, Level: 2 Type: Level 2 IS Hold Time: 9, Supported Protocols: ipv4, ipv6 SNPA: 2:1:0:b:0:0, Priority: 64 IPv4 Interface Address: 30.1.1.2 IPv6 Interface Address: fe80::1:ff:fe0b:0 Areas: 49.0001

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show isis neighbors

The show isis neighbors command displays IS-IS neighbor information.

Command ModeEXEC

Command Syntaxshow isis neighbors [INSTANCES] [INFO_LEVEL]show isis neighbors [INFO_LEVEL] VRF_INSTANCE


• <no parameter>

• instance_name


• <no parameter>

• detail


• <no parameter>

• vrf vrf_name

Display Values• Inst. ID

• System ID

• Type

• Interface

• SNPA

• State

• Hold time

• Area Address

Examples• This command displays general information about the IS-IS neighbors.

switch(config)#show isis neighbors

Inst Id System Id Type Interface SNPA State Hold time10 2222.2222.2222 L2 Vlan20 2:1:0:c:0:0 UP 3010 1212.1212.1212 L2 Vlan20 2:1:0:d:0:0 UP 910 3030.3030.3030 L2 Ethernet30 2:1:0:b:0:0 UP 9switch(config)#


2509

show isis network topology

The show isis network topology command displays a list of all connected devices in all areas.

Command ModeEXEC

Command Syntaxshow isis network topologyshow isis INSTANCES topologyshow isis network topology VRF_INSTANCE


• <no parameter>

• instance_name


• <no parameter>

• vrf vrf_name

Display Values• System Id

• Metric

• Next-Hop

• Interface

• SNPA

Examples• This command displays forwarding state for ports mapped to all VLANs.

switch>show isis network topology

ISIS Instance: Osiris VRF: default ISIS IP paths to level-2 routers System Id Metric Next-Hop Interface SNPA 00e0.52b5.7800 20 10.110.2.1 1/7 00e0.22b5.5843switch>

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• This command displays detailed information about the IS-IS neighbors.

switch(config)#show isis neighbors detail

Inst Id System Id Type Interface SNPA State Hold time10 2222.2222.2222 L2 Vlan20 2:1:0:c:0:0 UP 26 Area Address(es): 49.0001 SNPA: 2:1:0:c:0:0 Advertised Hold Time: 30 State Changed: - LAN Priority: 64 IPv4 Interface Address: 10.1.1.3 IPv6 Interface Address: fe80::1:ff:fe0c:0 Interface name: Vlan2010 1212.1212.1212 L2 Vlan20 2:1:0:d:0:0 UP 7 Area Address(es): 49.0001 SNPA: 2:1:0:d:0:0 Advertised Hold Time: 9 State Changed: - LAN Priority: 64 IPv4 Interface Address: 10.1.1.2 IPv6 Interface Address: fe80::1:ff:fe0d:0 Interface name: Vlan20switch(config)#


2511

show isis segment-routing adjacency-segments

The show isis segment-routing adjacency-segments command displays the global adjacency SIDvalue and other related information.

Command ModeEXEC

Command Syntaxshow isis segment-routing adjacency-segments

Examples

• In this example the show isis segment-routing adjacency-segments command displays theoutput for the interface configured like this:

interface Ethernet1 ip address 1.1.1.1/24 ipv6 address 1000::1/64 isis enable isis1 isis network point-to-point adjacency-segment ipv4 p2p index 1 global adjacency-segment ipv6 p2p index 2 global

• The show output for the above interface configuration:

Switch# show isis segment-routing adjacency-segments

System ID: 1000.0000.0002 Instance: isis1SR supported Data-plane: MPLS SR Router ID: 1.1.1.4Adj-SID allocation mode: SR-adjacenciesAdj-SID allocation pool: Base: 100000 Size: 16384Adjacency Segment Count: 2Flag Descriptions: F: Ipv6 address family, B: Backup, V: Value L: Local, S: Set

Segment Status codes: L1 - Level-1 adjacency, L2 - Level-2 adjacency, P2P - Point-to-Point adjacency, LAN - Broadcast adjacency

Locally Originated Adjacency SegmentsAdj IP Address Local Intf SID SID Source Flags Type ---------------- ---------- ------ ------------- --------------- ------- 1.1.1.2 Et1 1 Configured F:0 B:0 V:0 L:0 S:0 P2P L1fe80::1:ff:fe65:0 Et1 2 Configured F:1 B:0 V:0 L:0 S:0 P2P L1

Received Global Adjacency Segments SID Originator Neighbor Flags --------- -------------------- ---------------- --------- 0 rtrmpls1 1000.0000.0002 F:0 B:0 V:0 L:0 S:0

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• The following is the C-API output for the show isis segment-routing adjacency-segmentscommand.

Arista# show isis segment-routing adjacency-segments | json{ "vrfs": { "default": { "isisInstances": { "isis1": { "routerId": "1.1.1.4", "adjSidPoolSize": 16384, "receivedGlobalAdjacencySegments": [ { "systemId": "1000.0000.0001", "hostname": "rtrmpls1", "sid": 0, "flags": { "s": false, "b": false, "v": false, "f": false, "l": false }, "nbrSystemId": "1000.0000.0002" } ], "systemId": "1000.0000.0002", "adjSidAllocationMode": "SrOnly", "dataPlane": "MPLS", "adjacencySegments": [ { "lan": false, "sidOrigin": "configured", "flags": { "s": false, "b": false, "v": true, "f": false, "l": false }, "sid": 1, "localIntf": "Ethernet1", "ipAddress": "1.1.1.2", "level": 1 }, { "lan": false, "sidOrigin": "configured", "flags": { "s": false, "b": false, "v": false, "f": true, "l": false }, "sid": 2, "localIntf": "Ethernet1", "ipAddress": "fe80::1:ff:fe65:0", "level": 1


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} ], "adjSidPoolBase": 100000, "misconfiguredAdjacencySegments": [] } } } }

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show isis summary

The show isis summary command displays information about the configured IS-IS instances.

Command ModeEXEC

Command Syntaxshow isis summaryshow isis [INSTANCES] summaryshow isis summary VRF_INSTANCE


• <no parameter>

• instance_name


• <no parameter>

• vrf vrf_name

Display Values• System ID

• IPv4 Preference

• IPv6 Preference

• IS-Types

• LSP Generation interval

• SPF Interval

• Current SPF Hold Interval

• IS-Types Run Time

• Area Addresses

• Designated Intermediate Systems (DIS) Interfaces

• Link State Database (LSDB) size

Display Status• Multi Topology

• Authentication Mode

• Graceful Restart

• Graceful Restart Helper


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Example• This command displays general information about the configured IS-IS instances.

switch(config-router-isis-af)#show isis summary

IS-IS Instance: 1 VRF: default System ID: 0000.0000.0001, administratively enabled Multi Topology disabled, not attached IPv4 Preference: Level 1: 115, Level 2: 115 IPv6 Preference: Level 1: 115, Level 2: 115 IS-Type: Level 1 and 2, Number active interfaces: 0 Routes both IPv4 and IPv6 Max wait(s) Initial wait(ms) Hold interval(ms) LSP Generation Interval: 5 50 50 SPF Interval: 2 1000 1000 Current SPF hold interval(ms): Level 1: 1000, Level 2: 1000 Last Level 1 SPF run 1 seconds ago Last Level 2 SPF run 1 seconds ago Authentication mode: Level 1: None, Level 2: None Graceful Restart: Disabled, Graceful Restart Helper: Enabled Area Addresses: 49.0001 level 1: number dis interfaces: 0, LSDB size: 1 level 2: number dis interfaces: 0, LSDB size: 1

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shutdown (IS-IS)

The shutdown command disables IS-IS on the switch without modifying the IS-IS configuration.

The no shutdown and default shutdown commands enable the IS-IS instance by removing theshutdown command from running-config.


Command Syntaxshutdownno shutdowndefault shutdown

Examples• These commands disable IS-IS on the switch.

switch(config)#router isis Osirisswitch(config-router-isis)#shutdownswitch(config-router-isis)#

• This command enables IS-IS on the switch.

switch(config)#router isis Osirisswitch(config-router-isis)#no shutdownswitch(config-router-isis)#


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spf-interval

The spf-interval command sets the Shortest Path First (SPF) timer that defines the interval betweenIS-IS path calculations. The default value is two seconds.

This command also configures the maximum wait interval between any two SPF runs, initial waitinterval before executing the first SPF computation, and the hold time between the first and secondSPF runs.

The no spf-interval and default spf-interval commands restore the default maximum IS-IS pathcalculation interval to two seconds by removing the spf-interval command from running-config.

For information about viewing SPF interval values, see Verify IS-IS Instance Information.


Command Syntaxspf-interval max-wait [initial-wait | hold-time]default spf-intervalno spf-interval

Parameters• max-wait Value ranges from 1 through 300 seconds. Default maximum wait interval is two

seconds.

• initial-wait Value ranges from 1 through 300000 ms. Default initial wait interval is 1000 ms.

• hold-time Value ranges from 1 through 300000 ms. Default hold interval is 1000 ms.

GuidelinesEOS does not support configuring topology-specific SPF timers in multi-topology deployments andIS-IS level-specific SPF timers.

Examples• This command configures the SPF maximum wait interval to 50 seconds.

switch(config)#router isis Osirisswitch(config-router-isis)#spf-interval 50

• This command configures maximum wait interval, initial wait interval, and hold time to 20 seconds,10000 ms, and 5000 ms respectively.

switch(config)#router isis inst1switch(config-router-isis)#spf-interval 20 10000 5000

• This command reverts the SPF interval configuration to its default value.

switch(config)#router isis Osirisswitch(config-router-isis)#no spf-interval

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