Troubleshooting vLE

To troubleshoot vLE link state tracking, refer to the examples in the Configuring Virtual Link Extension State Tracking section. In particular, for both individual vLE pseudo-wires and redundant vLE trunks protocol messages can be leveraged to verify end-to-end connectivity (or lack thereof). LLDP messages (and LACP messages in case of trunks) show the neighboring port ID(s) and reflect the up/down connectivity status of the pseudo-wire(s). Therefore they are very valuable troubleshooting tools.

With vLE link state tracking enabled, a vLE pseudo-wire can go down (i.e., in vle-wait state) when the remote end of the vLE goes down. However, in some cases, it may be possible that a “false positive” event occurs in which the local vLE port goes down even if the remote end is physically up. This could happen if the vLE tracking logic incorrectly believes the remote end to be unreachable. In such case, you can disable vLE tracking, which should bring the local port back up and allow you to check if the traffic is flowing through the vLE pseudo-wire correctly. Increasing the vLE tracking timeout can help to avoid false positives by giving more leeway to the link state tracking software, especially when experiencing frequent link flaps or CPU overload conditions (which could affect the tracking logic negatively).