[j-nsp] BFD Distributed Mode for IPv6

[Mark Tinka]

On 2/Oct/18 21:13, James Bensley wrote:

> I presume that if one were to run MT-ISIS there would be no impact to IPv4?

We already run MT for IS-IS. I consider this as basic a requirement as
"Wide Metrics".

However, the issue here is BFD sees the whole of IS-IS as a client. So
if BFD has a moment, it will signal its client (IS-IS), regardless of
whether the moment was for IPv4 or IPv6.

I imagine that re-running adjacencies and SPF just for the IPv6 topology
would be a vendor-specific solution to the problem. However, wouldn't it
just be easier to support BFD for IPv6 in the PFE as Juniper already
does for IPv4?

> I'd be interested to know if BFD works OK if you use public IPv6
> addresses for IS-IS adjacencies (although it's a waste of IPs, I'd
> still be curious).

Interesting.

What I do know is that if you are running BFD for static IPv6 routes, it
runs in the PFE. But if the routes are learned via an IGP (IS-IS or
OSPFv3), it can only run in the RE.

Mark.