Just shooting in the dark, Isn’t the PSNP padded to some ISIS defined max MTU and that somehow fails due to mismatch on em0 L2 MTU?

adam

From: NANOG <nanog-bounces@nanog.org> On Behalf Of Mark Tinka
Sent: Friday, April 17, 2020 11:05 AM
To: nanog@nanog.org
Subject: IS-IS Error (FRR)

Hi all.

I'm almost there getting IS-IS to work without issue. I'm now faced with the following error log:

2020/04/17 10:02:01 ISIS: IS-IS bpf: could not transmit packet on em0: Input/output error
2020/04/17 10:02:01 ISIS: [EC 67108865] ISIS-Snp (1): Send L2 PSNP on em0 failed

This repeats every second.

Anyone know what this could be?

Systems is FreeBSD-12.1-RELEASE-p3.

Despite the error, IS-IS is running and routing is good, talking to a Cisco IOS XE implementation on the other side. So the error is throwing me off.

No feedback from the Slack feed, Google doesn't say much, and waiting to hear back from the FRR list.

Mark.