Brief Cisco-Centric Tutorialon IPv6 Peering

Version 1.0April, 2007Steve GibbardPacket Clearing House

Just Like IPv4 Peering, Sort Of...

Groups of routers form an ASYou set up peering between routersYou use “neighbor” configuration statements under a “router bgp ASN” configuration statement

...But You Do It On An IPv6 Network.

You need “ipv6 routing” configured on your routerAny interfaces forwarding IPv6 traffic need IPv6 interface addressesRouting tables are maintained separatelyEntirely new set of peering sessions

...But You Do It On An IPv6 Network.

Running IPv4 and IPv6 on the same routers and circuits does not mean that your IPv4 and IPv6 networks can talk to each other. They can’t.If you turn on IPv6 on your hosts, and something they’re trying to reach has an IPv6 DNS entry, your hosts will try to use it. Be very careful if your IPv6 connectivity isn’t as full and robust as your IPv4 connectivity.

Configuration Syntax

There Are a Few Syntactic Differences

Configuration statements must be preceded by “address-family ipv6”This messes up your IPv4 config syntax as wellWord-order of configuration changes“show ip bgp” becomes “show bgp ipv6”Except, that doesn’t work either. You need “show bgp ipv6 unicast”. Why? Who knows?

You’re All Familiar With IPv4 Peering...

router bgp 65534 neighbor PEER peer-group neighbor PEER route-map PEER-IN in neighbor PEER route-map PEER-OUT out neighbor 192.168.0.1 remote-as 65535 neighbor 192.168.0.1 peer-group PEER neighbor 192.168.0.1 password PASSWORD neighbor 192.168.0.1 description Sample peerend

...Which Changes a Bit...

router bgp 65534 neighbor PEER peer-group neighbor 192.168.0.1 peer-group PEER neighbor 192.168.0.1 description Sample peer neighbor 192.168.0.1 password PASSWORD address-family ipv4 neighbor PEER activate neighbor PEER route-map PEER-IN in neighbor PEER route-map PEER-OUT out neighbor 192.168.0.1 peer-group PEER

...And Adds IPv6 Configuration.

router bgp 65534 neighbor V6-PEER peer-group neighbor 2001:418:0:5000::31 remote-as 65535 neighbor 2001:418:0:5000::31 description Sample neighbor 2001:418:0:5000::31 password PASSWORD address-family ipv6 neighbor V6-PEER activate neighbor V6-PEER route-map V6-PEER-IN in neighbor V6-PEER route-map V6-PEER-OUT out neighbor 2001:418:0:5000::31 activate

Route-Maps and Prefix Lists

ipv6 prefix-list OUR-SPACE seq 5 permit 2001:478:9200::/48ipv6 prefix-list OUR-SPACE seq 15 permit 2001:503:8028::/48ipv6 prefix-list OUR-SPACE seq 20 permit 2001:503:D1AE::/48ipv6 prefix-list OUR-SPACE seq 25 permit 2001:503:A124::/48route-map V6-PEER-OUT permit 10match ipv6 address OUR-SPACEset community 65535:12345Note that they only change their identifier from “ip” to “ipv6”.

Diagnostic Syntax

Commands Look Familiar

show bgp ipv6 unicast summaryshow bgp ipv6 unicast xxx:xxx::/xxshow bgp ipv6 unicast neighbor xxx:xxx:xxx::xshow bgp ipv6 unicast neighbor xxx:xxx:xxx::x advertisedshow bgp ipv6 unicast neighbor xxx:xxx:xxx::x received

Output Looks Similar Too

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd2001:418:0:5000::31 4 2914 1849146 955659 13078783 0 0 2w3d 6972001:478:9200:51::7 4 65535 490551 1894528 13078783 0 0 6w5d 22001:478:9200:51::8 4 65535 490535 1894530 13078783 0 0 6w5d 22001:478:9200:FFFF::2

Output Looks Similar Too

router# sh bgp ipv6 unicast neigh 2001:478:9200:51::8 routesBGP table version is 13079261, local router ID is 204.61.209.254Status codes: s suppressed, d damped, h history, * valid, > bestOrigin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path* 2001:5EF:8028::/48 2001:478:92FF:51::8 0 0 65535 i* 2001:5EF:A124::/48 2001:478:92FF:51::8 0 0 65535 iTotal number of prefixes 2

But This is All Technical......and Peering is Business.

The Hard Part is Negotiating Agreements

Fortunately, this is kind of like IPv4 too.You call or email potential peers and ask them to peer.They say yes or no.Or maybe they ask “what’s peering?”Depending how important it is, you might try to convince them.

Except:

There isn’t much IPv6 traffic.Traffic analysis won’t tell you much (yet?).Nobody has any short-term financial incentive to make this work well.So don’t expect the sort of response you get when talking about IPv4 peering.

There’s a Good Side to This

As long as there’s no money in it, even the big networks are just playing.Since the big networks want connectivity to play with, they’ll peer with smaller networks, for now.

Thanks, and Questions?

Copies of this presentation can be foundin Keynote, PDF, and QuickTime formats at:http:// www.pch.net / resources / tutorials / ipv6-peeringSteve GibbardNetwork ArchitectPacket Clearing Housescg@pch.net