By default, when one interface in Virtual Wire loses its connection (link down), it propagates that state to the other interface in the Virtual Wire to facilitate a faster failover and communicate topology changes to neighboring devices.
Details
From the CLI, enable or disable this option using the following command:
> configure
# set network virtual-wire <virtual-wire-name> link-state-pass-through enable {yes|no}
In the WebGUI, go to Network > Virtual Wire:
Note: Ensure that both interfaces are set to 'auto' for the link state under Network > Interfaces > Advanced. If an interface is configured to 'up,' the link state remains up on the interface, regardless of connection state.