IPv6 - iBGP Session

[Plout0n]

Hello all,

I'm a little confused on iBGP and IPv6. Here is our setup:

We have a Nexus 3000 which houses our VLANS and serves as our layer 2 device. Our eBGP sessions are on a Juniper MX960. 

We want to start routing our IPv6. I've done BGP for IPv4 and understand the process, but IPv6 I'm a unsure. 

Does IPv6 require it's own iBGP link between the 2 or can it run over the existing IPv4 iBGP link? 

Here is how I have it setup now, certain data removed. 

 address-family ipv4 unicast
address-family ipv6 unicast
neighbor xxxx.xxxx::2 remote-as xxxx
description ipv6 ibgp
address-family ipv6 unicast
next-hop-self
soft-reconfiguration inbound
neighbor xxx.xxx.xxx.xxx remote-as xxxx

description ipv4 ibgp
address-family ipv4 unicast
next-hop-self
soft-reconfiguration inbound

With it setup like this, will it require it's own 10 Gb uplink in order to work or will this run over the existing 10 Gb uplink? I've tried to find info on routing IPv6 over IPv4 like JunOS allows, but haven't found anything. 

[Harold Ritter]

Some OSes (JUNOS, IOS) allow you to advertise IPv6 updates over an IPv4 transport. The best practice is to advertise IPv6 updates over an IPv6 transport (IPv6 BGP session) and IPv4 updates over IPv4 transport (IPv4 BGP session).

> With it setup like this, will it require it's own 10 Gb uplink in order to work or will this run over the existing 10 Gb uplink?

You can run both IPv4 and IPv6 sessions over the same link. No need for a dedicate link for IPv6 and IPv4.

Regards,

[Plout0n]

@Harold Ritter 

Thank you for your response. Let me see if I can explain this better.

When doing IPv4 iBGP, we set it up as such:

interface Vlan603
no shutdown
no ip redirects
ip address xxx.xxx.xxx187/29

With the neighbor IP being the network IP of the range.

neighbor xxx.xxx.xxx186 remote-as xxxx
description rr03.mx960.wlkspa
address-family ipv4 unicast
next-hop-self
soft-reconfiguration inbound

The thing I am having issues understanding is IPv6 and how a network IP translates.

I have it setup currently as

interface Vlan603
no shutdown
no ip redirects
ip address xxx.xxx.xxx.187/29
ip verify unicast source reachable-via rx
ipv6 address xxxx:xxxx::1/125

neighbor xxxx:xxxx::2 remote-as xxxxx
description ipv6 ibgp
address-family ipv6 unicast
next-hop-self
soft-reconfiguration inbound

This doesn't feel right. Would it be better doing this via the loopback IP for IPv6? 

Or would the range in the VLAN need to be xxxx:xxxx::2/125 with the neighbor IP being xxxx:xxxx::1?

I apologize if this is confusing or not properly explained. 

[Harold Ritter]

> This doesn't feel right. Would it be better doing this via the loopback IP for IPv6? 

No need to use the loopback IP for IPv6, no more than for IPv4. 

> Or would the range in the VLAN need to be xxxx:xxxx::2/125 with the neighbor IP being xxxx:xxxx::1?

Your IPv6 address and the one you peer with should be discussed with your service provider.

Regards,

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