- Is LOOP (Ethernet keepalive) only sent on ports in spanning-tree forwarding state?
- Does LOOP gets forwarded the same as traffic on other traffic on native VLAN (inbound untagged traffic)? So LOOP frame may get tagged on the outbound port?
- What kind of loop only LOOP can catch, spanning-tree can't? spanning-tree should be able to catch native VLAN mismatch or access VLAN mismatch using PVID TLV?
- If access VLAN or native VLAN is configured to a non-existent VLAN, how does this affect LOOP?
I am having an issue that ports get err-disabled for loopback. 3750, all copper links, keepalive running on all ports. But it isn't obvious what is causing the issue.
