[j-nsp] [c-nsp] Stange issue on 100 Gbs interconnection Juniper - Cisco

[Saku Ytti]

On Sun, 11 Feb 2024 at 15:24, james list <jameslist72 at gmail.com> wrote:

> While on Juniper when the issue happens I always see:
>
> show log messages | last 440 | match LACPD_TIMEOUT
> Jan 25 21:32:27.948 2024  MX1 lacpd[31632]: LACPD_TIMEOUT: et-0/1/5: lacp current while timer expired current Receive State: CURRENT
....
> Feb  9 16:39:35.813 2024  MX1 lacpd[31632]: LACPD_TIMEOUT: et-0/1/5: lacp current while timer expired current Receive State: CURRENT

Ok so problem always starts by Juniper seeing 3seconds without LACP
PDU, i.e. missing 3 consecutive LACP PDU. It would be good to ping
while this problem is happening, to see if ping stops at 3s before the
syslog lines, or at the same time as syslog lines.
If ping stops 3s before, it's link problem from cisco to juniper.
If ping stops at syslog time (my guess), it's software problem.

There is unfortunately log of bug surface here, both on inject and on
punt path. You could be hitting PR1541056 on the Juniper end. You
could test for this by removing distributed LACP handling with 'set
routing-options ppm no-delegate-processing'
You could also do packet capture for LACP on both ends, to try to see
if LACP was sent by Cisco and received by capture, but not by system.


-- 
  ++ytti