IPv6 tutorial - GARR · • Destiny options • Atuthentication • ICMP • Completely new •...

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RedIRIS – Miguel Angel [email protected]

IPv6 tutorial

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Agenda

• History• Why IPv6• IPv6 addresses• Autoconfiguration

• DNS• Transition mechanisms• Security in IPv6• IPv6 in Windows and Linux• IPv6 now

History

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• 70s• TCP/IP – developed in 1973, part of a project of the

Department of Defense (ARPA agency, USA)• ARPAnet network• Universities and Research centers computers networks connection

History

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• 80s• 1983, ARPAnet starts using TCP/IP• 1986, NSF (National Science Foundation) begins

the development of NFSnet, it will be the ARPAnet substitute, being the base of the Internet

History

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• 90s• 1993, first previsions of exhaustion of IPv4

addresses• IETF (Internet Engineegin Task Force) develops

IPv6 specifications• Initially it was IPng

• ¿What happens with IPv5?• Packets were marked with the version number 5, when the packets carried an experimental protocol, called ST, real time streaming.

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Agenda



Why IPv6

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• The main reason, more addresses

• But, what happens if I don’t need more addresses?– IPv6 is in fashion– Don’t loose the oportunity– Simplify end to end connections– No more NATs for security

• Tecnically:– All in one– Security in network layer– Autoconfiguration– More efficient and jerarquical routing

– We start again– Headers are more simple

Why IPv6

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• And now we have a lot of devices connected to a network, even TVs, cameras, fridges…everything!

Why IPv6

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• Countries with lack of IPv4 addresses

• Increasing demand

• Companies adopting and introducing IPv6

• IPv6 support will be necessary to not be disconnected of part of the network and internet

• IPv6 is robust, no patches

• Anyway…maybe IPv4 will not disappear

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Agenda



IPv6 header

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• It’s more simple

IPv6 header

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• CLASS is the Type of Service in IPv4• HOP LIMIT is the TTL of IPv4• FLOW LABEL is used in QoS• PAYLOAD LENGTH is the data length carried by the

packet• NEXT HEADER

• If I have more info, I use more headers…• No checksum• No fragmentation, only end to end

• MTU discovery

IPv6 header

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• Types of header extensions• Routing• Fragmentation• Hop-by-hop options• Destiny options• Atuthentication

• ICMP• Completely new• Including IGMP

IPv6 addresses

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• IPv4 – 4000 million of addresses

– Allocation without control

– Fragmentation

• IPv6 – 3.4x10^38 addresses

– Clean slate, we start from scratch. Control, order.

– 128 bits to addres the world

IPv6 addresses

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• 4 times bigger

– 32 to 128 bits

• Sintax:– aaaa:bbbb:cccc:dddd:eeee:ffff:0000:1111

– Hexadecimal digits in groups of 4– You can substitute a group of 0s by ::– No masks, instead we have /number_of_bits (like

CIDR notation in IPv4)

IPv6 addresses

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• Addres format:

• Unicast, multicast, anycast• Global unicast addresses start with 001 (binary) so we

have addresses starting with 2 or 3– 2001::… or 3ffe::…

• No broadcast (instead, multicast)

IPv6 addresses

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• Interface-id• Last 64 bits of the address• Unique in a local network• The IPv6 address is asociated with the

interface, not the host• MAC address is mapped

IPv6 addresses

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• Hosts addresses• When I have IPv6 configured or enabled

in a host, I automatically have a link-local address

• Starts with fe80::• Not routeable• Is unique in the local network• That address is configured automatially

using the interface-id• Used for autoconfiguration

IPv6 addresses

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• Multicast addresses• Start with FF00

• First 0 is Flags – (0,1 – permanent, not permanent)• Second 0 is scope

• 1 – node• 2 – link• 5 – site• 8 – organization• E – global

• FF02::1 – all the nodes of a network• FF02::2 – all the routers of a network

IPv6 addresses

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• Anycast addresses• Used for a group of interfaces with the same address

• One packet sent to that address goes to the nearest host with that address

IPv6 addresses

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• Example of global addresses:• IPv4: 130.206.1.159• IPv6: 2001:0720:0418:cafe:cccc:1111:abeb:b0b0

• We can summarize:• 2001:720:0000:0000:0000:0000:0000:9876 is• 2001::9876• 2001:720:0000:0000:0000:0000:0000:0000 is• 2001:720::• ¿What will be ::/0 ?

IPv6 addresses

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• How we can distribute my prefix in my network?

• To each one of the centers I can assign a /48– First 48 bits are fixed

• A network is a /64– Interface ID

• I have 16 bits to distribute the addresses in my center– Network ID

IPv6 addresses

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• Example, RedIRIS have 2001:0720::/32 for all the Universities and Research centers

Company/Building

Department Department

IPv6 addresses

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• Special addresses• Loopback (127.0.0.1) is ::1• Default(0.0.0.0/0) is ::/0• IPv6 compatible with IPv4 (for tunnels)

::130.206.1.159• IPv6 mapped over IPv4

::FFFF:130.206.1.159• Link-local address, starts with fe80::

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Agenda

• History• WhyIPv6• IPv6 addresses• Autoconfiguration


Autoconfiguration

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• New IPv6 feature (similar to IPv6 DHCP)• Network administration is easier – plug and

play• The user connects the host to the network

and is automatically configured• Advantage over DHCP

• It’s not necessary an additional server

Autoconfiguration

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• Protocol used here is neighbor discovery• Hosts and network equipment exchange multicast IPv6 packets to check the host IPv6 address

• Duplicate IPv6 addresses detection• Two types

• Stateful and stateless• Different mechanisms that can be used in a complementary way

Autoconfiguration

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• Stateful• Manual configuration, or using DHCP

• Like IPv4• Stateless

• Completely automatic configuration• It’s not necessary the manual config of hosts and servers. In some cases, we need minimal network equipment configuration (routers)

Autoconfiguration

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• Neighbour advertisement• The host send a router request message

• ICMP type 133• The router sends a router advertisement

message • ICMP type 134• Include the prefix announced by the

router with the TTL

Autoconfiguration

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• The host sends the neighbour request message to check the IPv6 address of the neighbour• ICMP type 135

• A neighbour advertisement message is sent• A router can send a change or redirection

message to find the best hop for a destiny

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Agenda



DNS

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• Now, applications behave in a different way• First, they request the IPv6 addres(timeout…)• If it’s coded correctly, it will ask for IPv4

– You have to be very careful when putting an IPv6 service in production

• Good connectivity– You have to be very careful when configuring an

IPv6 address in the DNS• Deny of service!

DNS

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www.ipv6.elmundo.es

2001:800:400:10::71

Access to the webserver (port 80)

Port 80 not reachable

DNS

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– I have configured all the hosts in my network,

– Also my router

• DNS is a must, due to the length of the

addresses

– Bind v9 support IPv6 addresses

• IPv6 requests over IPv6:» options {

listen-on-v6 { any; };}

• IPv6 requests over IPv4

DNS

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• It’s better not to create an special zone for IPv6 (like ipv6.my_center.com)

• But, it can be dangerous for production services

• During tests, it’s better ftp.ipv6.my_center.com than ftp.my_center.com

• Anyway, we should go for the same direct zone

– Direct zone– We use the same config files as with IPv4 (AAAA

instead of A)

ftp://ftp.my_center.com

DNS

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• Reverse zone• nibble-bit notation with .arpa

– 0.2.7.0.1.0.0.2.ip6.arpa– Root servers are configured to support this format– Recommended and the zone which is delegated

with the Registries (like RIPE)– Latests versions of glibc support this format

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Agenda



Transition

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• We cannot switch off the Internet and then switch on with IPv6

• There are several mechanisms• IPv4 and IPv6 can live together

• BUT IPv4 and IPv6 are not compatible• Three types of transition mechanisms

• Dual-stack• Based on tunnels• Based on address translation

Transition

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• Dual-stack• We depend on vendors implementations• My equipment support native IPv4 and native IPv6, at the the same time, parallel.

•More operational effort• I can plan a periodic migration, step by step

•Network•Servers

•Applications and services•Hosts

• The best one• It’s recommended a testing period

Transition

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• Tunnels• IPv6 traffic is encapsulated in IPv4 packets• I connect two IPv6 worlds separated by an IPv4 domain

• Automatic tunnels• The host has an IPv4 compatible IPv6 address

• 6to4: IPv4 address of the tunnel endpoints are identified in the IPv6 prefix

» We use 2002::/16• Manual tunnels

• Explicit configuration• IPv4 tunnel endpoints• IPv6 address of the tunnel interface

• Tunnel brokers•Automatic configuration to have basic IPv6 connectivity if my network is only IPv4

Transition

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• 6to4• I connect two IPv6 worlds isolated (IPv4 between them)•The router to the Internet creates a 6to4 tunnel to the other domain•The IPv4 addresses of the tunnel endpoints are included in the IPv6 prefix•Used 2002::/16

• Teredo•Provides IPv6 connectivity behind a NAT•Encapsulates IPv6 packets into UDP IPv4

•They can go through the NAT and the Internet

Transition

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• To migrate all my network to IPv6 I’ll have the following problems:

• My hardware doesn’t support IPv6– Upgrade it– Use a Linux router – Use an alternate router, with a tunnel to a

provider– I have a firewall

» Not a lot of solutions» Upgrade is important

Transition

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Level 2 migration, integrating an IPv6 router in

the same vlan

Small IPv6

router

Transition

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More natural migration, including dual-stack

Transition

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Migration using Level 3

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Agenda



Security

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• Support for IPv6+firewalls+tunnels is not widely deployed

• But IPv6 has IPsec…• The same as with IPv4, but in that case is part

of the protocol (security header), less problems

– Security is included, as part of the IPv6 specifications

– Authentication– Encryption

Security

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• With the right security policies, it’s not a problem to have public addresses for everyone.• It’s easier the network administration

• NAT is not necessary • Problems with multimedia applications• Problems with IPsec• Problems with multicast• Problems with end to end, peer to peer and

point to point applications

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Agenda



IPv6 & Windows

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• www.microsoft.com/ipv6• You can create an IPv6 tunnel against Micrsoft

• Good for testing• With windos 2000 you have to install SP2• With Windows XP

• With SP1 or higher• It’s part of the system• To install it

• Form properties of my network places• Using CLI

• Netsh interface ipv6 install• Without SP1

• You cannot do DNS queries using IPv6• Install it using CLI

• Ipv6 install

IPv6 & Windows

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• www.microsoft.com/ipv6• With windows Vista *With MAC (live show)

• Installed by default• You can deactivate it

IPv6 & Linux

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• In the latests versions, kernel has complete IPv6 support– If my host has IPv6 activated

• In my loopback address I’ll see:::1/128 Scope: Host

• In the interfaces I’ll see a link-local address

eth0 Link encap:Ethernet HWaddr 00:60:08:3A:9E:B7inet addr:130.206.1.157 Bcast:130.206.1.255

Mask:255.255.255.128

inet6 addr: fe80::260:8ff:fe3a:9eb7/10 Scope:Link…

– My host will be configured using the prefix that the router announces, having complete IPv6 connectivity

eth0 Link encap:Ethernet HWaddr 00:60:08:3A:9E:B7inet addr:130.206.1.157 Bcast:130.206.1.255 Mask:255.255.255.128 inet6 addr: 3ffe:3328:5:1:260:8ff:fe3a:9eb7/64 Scope:Globalinet6 addr: fe80::260:8ff:fe3a:9eb7/10 Scope:Link

IPv6 & Linux

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• http://www.bieringer.de/linux/IPv6/• How-to• State of the art• Testing URLs

http://www.bieringer.de/linux/IPv6/

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Agenda



IPv6 now

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• Only the lack of addresses promoted the born of IPv6

• When IPv4 addresses are going to be exhausted?• 2012 ¿?

• But:• It seems that we still have the 35% of IPv4

address space available• Internet double its size each year

• NAT allows sharing addresses

IPv6 now

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• Not equal deployment• Asian countries with expanding economies or

high population density• China/Japan• Quick deployment

• In Europe/USA, no lack of addresses• Very slow deployment

IPv6 now

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• Academic and research networks• 90% of European and American networks provide native IPv6• Very few traffic, about 5-10%• A good starting point• We have the base for the commercial deployment• The killer application?

IPv6 now

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• In Spain• 4% of Telcos provide IPv6 services

• research projects or testbeds• more or less, ready

•There is no client requirements•RedIRIS

• We offer IPv6 services since 1997• 15% of the centers with native IPv6 connection• 25% of the final users• Few traffic, about 7% of the total

Finally

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• Transition cost• low CAPEX• High OPEX

• When IPv4 addresses will be finished?• ¿2020?, ¿2030?

–IPv4 probably will not disappear

–Very large transition period

–IPv6 has to be familiar, we have to start playing with it in our networks

IPv6 tutorial - GARR · • Destiny options • Atuthentication • ICMP • Completely new •...

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