25.5.2 Notes on L2 protocol frame transparency functionality

(1) Coexistence with other functions

See "22.3 Coexistence of Layer 2 switch function and other functions".

(2) UDLD forwarding function

When the Switch is connected between switches that use IEEE802.3ah/UDLD function and the Switch uses UDLD forwarding function, use a one-to-one configuration for the ports of both switches that exchange OAMPDU. Because the link status is not recognized between devices that use IEEE802.3ah/UDLD function, a unidirectional link failure may be erroneously detected.

Also, when the Switch uses VXLAN function and UDLD forwarding function to forward VXLAN tunnels, a unidirectional link failure may be erroneously detected depending on the status of VXLAN tunnel's network.

The following figure shows an example of the connection configuration.

Figure 25-5: Using UDLD forwarding feature between devices using IEEE802.3ah/UDLD facility

To detect a unidirectional link failure by mistake, use the configuration command efmoam udld-detection-count to adjust the number of times that a unidirectional link failure is identified for the device using IEEE802.3ah/UDLD function.

In a configuration in which a relay device is connected between devices that use IEEE802.3ah/UDLD function, even if a unidirectional link failure is detected on the device for which udld parameter is set by the configuration command efmoam active and the port goes inactive, link-down cannot be detected on the port of the remote device. To link down the ports of both devices, use efmoam active command. Set udld parameter on both devices.