Users Guide

Table Of Contents
Configure the VLT backup link using the backup destination {ip-address | ipv6 ipv6address} [vrf
management] [interval interval-time]. The interval range is from 1 to 30 seconds. The default interval is 30
seconds. Irrespective of the interval that is configured, when the VLTi link fails, the system checks for the heartbeat connection
without waiting for the timed intervals, thus allowing faster convergence.
NOTE: The VLT domain and the backup parameters are auto-configured in the SmartFabric Services mode from release
10.5.0 onwards.
Example configuration:
OS10(config)# vlt-domain 1
OS10(conf-vlt-1)# backup destination 10.16.151.110 vrf management interval 20
OS10(config)# vlt-domain 1
OS10(conf-vlt-1)# backup destination ipv6 1::1 vrf management interval 20
The following examples describe different cases where the VLT backup link is used:
In the following figure, the backup link is not configured:
Support for new streams during VLTi failure
If the VLTi fails, MAC addresses that are learned after the failure are not synchronized with VLT peers. Thus, instead of unicast,
the VLTi failure causes a continuous traffic flood.
If the VLTi links fail, MAC and ARP synchronization does not happen, and it causes the system to flood L2 packets and drop L3
packets.
Virtual Link Trunking
1629