Hi all.

So I finally decided to start messing around with FRR for a native IS-IS deployment for some of our FreeBSD-based Anycast services.

I hit an issue that I posted to the FRR list that hasn't progressed beyond identifying a bug:

2020/03/21 03:12:36 ISIS: isis_send_pdu_bcast: sock_buff size 8192 is less than output pdu size 9014 on circuit em0
2020/03/21 03:12:36 ISIS: [EC 67108865] ISIS-Adj (1): Send L2 IIH on em0 failed

This is being addressed here:

    https://github.com/FRRouting/frr/pull/6066

But my main question was if there was a command or setting in zebra.conf and/or isisd.conf that I can use to define the MTU IS-IS should use to set itself up, rather than being informed by what the interface currently runs at. I've tried everything that is documented as well as stuff that isn't, but nothing is accepted or recognized.

Either no one runs IS-IS on FRR, or much of the implementation is still being developed and/or hasn't been tested in the wild, i.e., no traction.

I'm hoping there is someone on this list that has played with IS-IS on FRR to point me in the right direction.

The setup is FRR 7.3 on FreeBSD-12.1. Thanks.

Mark.