Symptom
Multicast storms are seen in the fabric. This issue specifically affects glean packets of ether type 0xfff2, but other packets are also affected. Multiple ARP requests are seen on the end hosts. Link utilization can be so high that drops are seen.
Conditions
FX2 Leafs
Issue on spine switch that causes traffic to be sent down links that are not in the FTAG. If traffic on the spine switch is not sent to incorrect links, then there is not an issue.
Workaround
Only have links up to one spine switch on each FX2 leaf switch.
Further Problem Description
The issue is that we are bypassing a forwarding check on FX2 that should be dropping packets that are coming in on a link that is not a part of the FTAG; but in order for the issue to manifest, we must also have incorrect forwarding behavior on the Spine to send traffic down the link that is not in the FTAG tree.
