[c-nsp] STP over Port-channel issue

Saku Ytti saku at ytti.fi
Mon May 6 09:21:49 EDT 2024

On Mon, 6 May 2024 at 15:53, james list via cisco-nsp
<cisco-nsp at puck.nether.net> wrote:

> The question: since the PO remains up, why we see this behaviour ?
> are BDPU sent just over one link (ie the higher interfac e) ?


> how can we solve this issue keeping this scenario ?
> moving to RSTP could solve ?


I understand you want topology to remain intact, as long as there is
at least 1 member up, but I'm not sure we can guarantee that. I think
if you set LACP to fast, it'll fail in max 3s, and you ensure STP
fails slower (i.e. don't use rapid pvst), you probably will just see
BPDU switch physical interface, instead of STP convergence.

You'd need something similar to microBFD on LAGs, where BFD PDU is
sent on each member, instead of an unspecified single member, but
afaik this does not exist.

So what you really need is L3/MPLS topology :/.


More information about the cisco-nsp mailing list