Connectivity Guide

Prevention of loops during VLTi failure
When VLTi is down, STP may fail to detect any loops in the system, which creates data loop in an L2 network.
In the following illustration, STP is running in all the three switches. In the steady state, VLT peer 1 is elected as the root bridge.
When VLTi is down, both the VLT nodes become primary. In this state, VLT peer 2 sends STP BPDU to TOR assuming that TOR sends
BPDU to VLT peer 1. Due to this, VLT peer 2 does not receive BPDU on the VLT port, but receives TOR BPDU from orphan port. The STP
in VLT peer 2 assumes that there is no loop in the system and opens up both the VLT and the orphan ports. This creates a data loop in the
system which brings down the system.
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Virtual Link Trunking