Does disabling LACP affect service?

[IgorN]

Hi all, I tried to continue existing similar topic but perhaps it is better to start a new one.
I have 2x VSP7200 stacked switches connected with 4x10G ports in a LAG to a Cisco VHS cluster, at Cisco end it is a single PortChannel. Now we need to add new VLANs to this LAG and for that we have to disable and re-enable LACP on both VSP switches. Is this service-affecting? Obviously it will happen out of hours, but if it is affecting then the change window and amount of regression testing on the apps side, and overall perceived risk will be much larger.
Thanks!

[IgorN]

For those who will find this topic later, in real change we observed TCP links re-established between the two sides of the LAG, 4 links in the group were brought down two after two. Not sure though why this happened, TCP should be tolerant to the network connectivity gap whithin LACP convergence.time

[EXTR_Paul]

??

If it was all SPBm or MLT/SMLT it would be a different story. I have customers that would do that change in the middle of the day. However, from my experience LACP failover is not sub-second.

[IgorN]

Great, thanks! As I said, this will be out of hours, obviously during scheduled maintenance window.

[EXTR_Paul · Accepted solution]

Yes.

however I would still do this inside a maintenance window.

[IgorN]

Thanks Paul! Do you think this sequence is viable to avoid service interruption?
VSP-1: shutdown 2 interfaces > (LAG works on 2 links on VSP-2) > disable LACP > add VLANs > enable LACP > enable interfaces
VSP-2: shutdown 2 interfaces > (LAG works on 2 links on VSP-1) > disable LACP > add VLANs > enable LACP > enable interfaces