Issue/Introduction:
An interface configured as backup in an interface redundancy pair must be configured with the standby-only parameter.Some traffic may fail when an X-series system is configured with interface redundancy and the parameter standby-only is not set for the backup interface. Such an incomplete configuration can lead to connectivity issues since traffic is potentially received by both master and backup ports, especially if the associated VAP group is running in layer 2 mode.
Cause:
The standby-only parameter is a requirement for the backup interface when configuring interface redundancy. The XOS Command Reference documents this requirement for the backup interface in the following note (Chapter 7, Commands for Configuring Interface Redundancy):
NOTE: The specified interface must be configured to pass traffic
between the X-Series Platform and an external network. In
addition, the specified interface must be configured with the
standby-only (conf-intf-ether context) command.
Using the parameter standby-only ensures that the interface doesn't process traffic unless the master interface fails.
Resolution:
The parameter standby-only has to be configured for every interface declared as backup in the redundancy-interface command.
Workaround
N/A