[FROG] IS-IS MTU in FRR

[Mark Tinka]

On 21/Mar/20 14:26, Donald Sharp wrote:
> https://github.com/FRRouting/frr/pull/6066

Thanks, Donald.

So the box is running 9,000 bytes MTU on the interface in FreeBSD. For
various reasons, I'd prefer not to reduce that.

Is there any way to tell FRR to send IIH PDU's of 8,000 bytes? We
already do this in our production network because we run CSR1000v on
VMware for our route reflectors on servers with the same issue (VMware
can't handle an MTU larger than 9,000 bytes), and limiting the IS-IS
core to 8,000 bytes is how we got a stable network-wide IS-IS deployment
going.

So if I can tell FRR to run IS-IS at 8,000 bytes, I think we could go
forward. I just can't seem to find a command to add to zebra.conf or
isisd.conf to do this.

The documentation doesn't mention anything about setting interface or
protocol MTU's.

Any ideas where I can find this, if support does, in fact, exist?

Mark.