Reference Guide
OS10(config)# vlt-domain 1
OS10(conf-vlt-1)# backup destination ipv6 1::1 vrf management interval 30
The following examples describe dierent cases where VLT backup link can be used:
MAC and ARP not synchronized
When VLTi fails, MAC address learnt after the failure is not synchronized with VLT peers. This leads to continuous ooding of trac instead
of unicast.
Due to wrong hashing, ARP learning might fail leading to trac being dropped.
In the following illustration, after VLTi is down VLT peer 1 learns MAC address of Host 2.
As VLTi link fails, the VLT peer1 is not synched up with the MAC address of Host2 . Due to this, if the trac from Host1 is hashed to VLT
peer2, then the VLT peer2 oods the trac. Yet, the trac would not reach Host2 as the VLT port between VLT peer 2 and Swicth 3 is
down.
When VLT backup link is enabled, the secondary VLT peer 2 identies the node liveliness through the backup link. If the primary is up, the
secondary peer brings down the VLT LAG ports. Now the trac from Host1 reaches VLT peer 1 and then reaches the destination, that is
Host2. In this case the trac is unicasted instead of ooding, as shown in the following illustration.
Virtual Link Trunking
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