[c-nsp] ASR9k: RIB/FIB convergence

[Thomas Schmid]

Hi,

Am 21.08.2018 um 16:35 schrieb Thomas Schmid:
> Hi,
> 
> to give you an update: TAC finally could reproduce the issue  in the lab. RIB/FIB sync is thwarted when there's a VSM module installed in the chassis (which we have in all 9k chassis). 
> 
> Let's see if they can fix it with a SMU ...
> 

latest news: FIB updates are sent via the punt-switch (sort of regular ethernet switch on the RP) as multicast to all LCs. On A99-RP2-SE RPs this switch has flow control enabled. Now, the VSM LC answers to these updates with PAUSE frames and therefore the switch throttles the update rate to all LCs close to zero.

Good news: as a workaround you can disable flow-control to the punt-switch via CLI for specific LCs. 

I'm reluctant to share the CLI command here because it's very hardware specific and I don't want anybody to run into problems just because their hardware is slightly different from ours.

Cisco will provide a SMU in the next weeks that either disables flow-control on these LC or changes the throttle thresholds (not decided yet).

Cheers,

   Thomas