topic Re: SPBM/802.1Q Leading to Loop? in ExtremeSwitching (VSP/Fabric Engine)

SPBM/802.1Q Leading to Loop?

bfaltys24 — Tue, 14 Feb 2023 14:36:04 GMT

This morning I connected up a redundant link from one of our sites to an ISP. This link is running fabric extend. Shortly after, we had pretty significant packet loss across a lot of our sites. It seems like a loop and I'm guessing it is the fact the the ERS has 1 SPBM port and one 802.1Q tagged port (we intended to convert to SPBM after getting the secondary link up). Here is a diagram of the topology. Is my assumption of a loop accurate or am I missing something?

Re: SPBM/802.1Q Leading to Loop?

WillyHe — Wed, 15 Feb 2023 19:50:49 GMT

Hello,

If the link between the bottom switch and the middle right switch is the only 802.1Q tagged link and
All other links are SPBM-FC or SPBM-FE links, then,
When you have vlan's connected over the 802.1Q tagged link that also have the same I-SID's configured on both sides of this link, then YES you have created a perfect loop.

regards
WillyHe

Re: SPBM/802.1Q Leading to Loop?

EXTR_Paul — Wed, 01 Mar 2023 14:50:04 GMT

As WillyHe said, you have a loop. make that 802.1Q link an SPBm-NNI and this problem goes away.

Re: SPBM/802.1Q Leading to Loop?

WillyHe — Thu, 02 Mar 2023 13:46:35 GMT

You are correct Paul, I should have said that also 😕.