Users Guide

● When VLTi fails and the VLT heart-beat is down, both the VLT peers become primary (split brain).
● Ethernet1/1/1 in both the VLT peers are kept up.
● When VLTi recovers, election occurs.
● The port remains up in the peer elected as the primary node.
● In the secondary VLT peer, ethernet1/1/1 is brought down (since ignore vlti-failure configuration is disabled) and the
delay-restore timer is started. A syslog indicating that the delay-restore timer has started is thrown on the console.
● After the delay-restore timer expires, ethernet1/1/1 is brought up and a syslog is thrown on the console.
On VLTi failure, DROP-enabled ports are treated the same way as VLT LAGs (when ignore vlti-failure configuration is disabled)
in all scenarios; except in a scenario where VLT MAC (common MAC) is not configured and VLT heart-beat is down or not
configured.
If VLT MAC is not configured on the VLT peers, the primary VLT peer's MAC is used as the system ID in the LACP BPDUs.
When VLTi fails, the VLT peers become split-brain, as there is no VLT heart beat. Each VLT peer starts sending its own system
MACs as the system ID in the LACP BPDUs. As a result of this mismatch, the VLT LAG arm of the old secondary peer becomes
operationally down (since it changed its system ID from the primary's MAC to its own MAC) due to LACP protocol behavior.
In this scenario, the DROP configured orphan ports will not be brought down. Any incoming traffic from the orphan ports is
black-holed as the VLT LAG arm and VLTi are operationally down.
After VLTi recovers, both DROP-enabled ports and VLT LAGs are brought down in the peer elected as the secondary node for
running delay-restore timer. After the timer expires, DROP-enabled ports and LAGs are brought up.
NOTE: It is recommended to always have VLT MAC and heart-beat configured.
Following table lists the steps to configure orphan ports to ignore VLTi failures:
Table 149. Configure orphan ports to ignore VLTi failure
Steps Command Description
1
OS10# configure terminal
Enters
Configuration mode.
2
OS10(config)# interface ethernet 1/1/1
Enters Interface
configuration mode.
3
OS10(conf-if-eth1/1/1)# vlt delay-restore orphan-port
ignore-vlti-failure
Enables orphan port
to ignore VLTi fail
scenario.
4
OS10# show vlt 1 delay-restore-orphan-port
VLT Delay-Restore timer
: 90 seconds
Remaining time
: 60 seconds
Delay-Restore Orphan-Port enabled interfaces
: Eth1/1/1
Delay-Restore Orphan-Port Ignore VLTi Fail enabled
interfaces : Eth1/1/1
Displays the current
status of the
timer and delay-
restore orphan-port
configurations.
The following tables lists the steps to disable the delay-restore orphan ports:
Table 150. Disable delay-restore orphan ports
Steps Command Description
1
OS10# configure terminal
Enters
Configuration
mode.
2
OS10(config)# interface ethernet 1/1/1
Enters Interface
configuration
mode.
3
OS10(conf-if-eth1/1/1)# no vlt delay-restore orphan-port
ignore-vlti-failure
Disables orphan
port to ignore VLTi
failures.
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