Learning About Other Devices -Jp
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Cisco 2 - Routers Perrine. J Page 1 07/17/22 Chapter 4 Cisco Discovery Protocol (CDP) CDP is a layer 2 protocol. CDP is used to: • obtain information about neighboring devices • types of devices (switch, type of router) • router interfaces they are connected to • interfaces used to make the connection ( E0, S0, etc.) • model number of the devices CDP is protocol independent, and runs on Cisco equipment over the Subnetwork Access Protocol (SNAP).
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Transcript of Learning About Other Devices -Jp
No Slide TitleCDP is used to:
types of devices (switch, type of router)
router interfaces they are connected to
interfaces used to make the connection ( E0, S0, etc.)
model number of the devices
CDP is protocol independent, and runs on Cisco equipment over the Subnetwork Access Protocol (SNAP).
Cisco 2 - Routers
Cisco Discovery Protocol (CDP)
Primary use of CDP is to discover all Cisco devices that are directly connected to a local device.
This is done by transmitting type length values (TLVs) which are blocks of information embedded in CDP advertisements.
To display the CDP information, use the command:
show cdp neighbors
Cisco 2 - Routers
device ID
local interface
Native VLAN (CDPv2 only)
Cisco 2 - Routers
To enable CDP on a particular interface, do:
cdp enable
On Cisco IOS Release 10.2 or higher, CDP is enabled by default
Cisco 2 - Routers
Disable CDP at the global level, use no cdp run
If CDP is disabled globally, individual interfaces cannot be enabled for CDP
IOS Release 10.3 or higher, CDP is enabled by default. However, on asynchronous interfaces, CDP is disabled by default.
To disable CDP on a specific interface after it has been enable, do no cdp enable
Cisco 2 - Routers
Telnet
Telnet is a virtual terminal protocol that is part of the TCP/IP protocol suite.
Provides a remote login capability.
Telnet function at the application layer. If a telnet command is successful from one device to another, then all 7 layers of the OSI model is ‘working’.
It is the most complete testing mechanism available, say Cisco.
Telnet uses the five (5) vty sessions. However, there has to be a ‘login’ and password associated with the vty session in order for telnet to work.
Cisco 2 - Routers
Telnet
If one has a ‘host table’ on the router ( ip host <name> <ip add> ), then you can do telnet <host name>.
As an example:
NOTE:
Cisco 2 - Routers
Ping
Ping command is used to determine if a particular ip address is reachable.
Traceroute command is used to trance the route to an ip address.
Ping sends ICMP echo request messages and receive an echo reply.
Ping Command Code Explanation
! ICMP echo reply received
Cisco 2 - Routers
operational
Connection problems (L2)
Interface problems (L1)
disabled
Serial is up, line protocol is down maybe caused by:
network mismatched
types of devices (switch, type of router)
router interfaces they are connected to
interfaces used to make the connection ( E0, S0, etc.)
model number of the devices
CDP is protocol independent, and runs on Cisco equipment over the Subnetwork Access Protocol (SNAP).
Cisco 2 - Routers
Cisco Discovery Protocol (CDP)
Primary use of CDP is to discover all Cisco devices that are directly connected to a local device.
This is done by transmitting type length values (TLVs) which are blocks of information embedded in CDP advertisements.
To display the CDP information, use the command:
show cdp neighbors
Cisco 2 - Routers
device ID
local interface
Native VLAN (CDPv2 only)
Cisco 2 - Routers
To enable CDP on a particular interface, do:
cdp enable
On Cisco IOS Release 10.2 or higher, CDP is enabled by default
Cisco 2 - Routers
Disable CDP at the global level, use no cdp run
If CDP is disabled globally, individual interfaces cannot be enabled for CDP
IOS Release 10.3 or higher, CDP is enabled by default. However, on asynchronous interfaces, CDP is disabled by default.
To disable CDP on a specific interface after it has been enable, do no cdp enable
Cisco 2 - Routers
Telnet
Telnet is a virtual terminal protocol that is part of the TCP/IP protocol suite.
Provides a remote login capability.
Telnet function at the application layer. If a telnet command is successful from one device to another, then all 7 layers of the OSI model is ‘working’.
It is the most complete testing mechanism available, say Cisco.
Telnet uses the five (5) vty sessions. However, there has to be a ‘login’ and password associated with the vty session in order for telnet to work.
Cisco 2 - Routers
Telnet
If one has a ‘host table’ on the router ( ip host <name> <ip add> ), then you can do telnet <host name>.
As an example:
NOTE:
Cisco 2 - Routers
Ping
Ping command is used to determine if a particular ip address is reachable.
Traceroute command is used to trance the route to an ip address.
Ping sends ICMP echo request messages and receive an echo reply.
Ping Command Code Explanation
! ICMP echo reply received
Cisco 2 - Routers
operational
Connection problems (L2)
Interface problems (L1)
disabled
Serial is up, line protocol is down maybe caused by:
network mismatched
