Juniper <-> Cisco IPv6 BGP peering

Jen Linkova furry13 at
Fri Dec 9 07:14:07 UTC 2011

On Thu, Dec 8, 2011 at 11:53 AM, Randy Carpenter <rcarpen at> wrote:
> Tried that. I agree with others that it is an NDP issue. NDP for the GUA is fine, but just not for the link local. Is there something that would block only link local by default?
> I should add that I have another uplink to a different provider that works perfectly. The other end is Juniper for that one.

Just to begin with:
0) Does your Juniper device have the neighbor cache entry for Cisco
link-local address? What is the state of the entry?

Can you get packet capture on both sides?

1) is Cisco sending NS packets?
2) is your Juniper receiving them?
3) is Juniper device sending anything back?
4) are those NA reaching Cisco?

Any switch on the path?

[lazy mode on] I'd also suggest:
 - debug ipv6 nd on cisco
 - checking for bugs for IOS and JunOS versions you are using

> On Dec 7, 2011, at 17:53, Peter Rubenstein <peter216 at> wrote:
>> Try setting local-address in the bgp neighbor config on the Juniper side?
>> --Peter
>> On Dec 7, 2011, at 4:54 PM, Randy Carpenter <rcarpen at> wrote:
>>> Does anyone have any suggestions on setting up BGP peering between Juniper (SRX) and Cisco?
>>> I successfully have cisco-cisco and juniper-juniper without problems.
>>> When I am trying to peer to one of my upstreams (who has cisco) with my Juniper SRX, They are seeing the link-local address as the next-hop, but are unable to get an ND entry for it, and thus cannot forward traffic to me.
>>> -Randy
>>> --
>>> | Randy Carpenter
>>> | Vice President - IT Services
>>> | Red Hat Certified Engineer
>>> | First Network Group, Inc.
>>> | (800)578-6381, Opt. 1
>>> ----

SY, Jen Linkova aka Furry

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