Modifying a Trunk or VLAG Configuration by Changing the LACP Mode


You can now modify a trunk or VLAG configuration by changing the LACP fallback mode and timeout.


This feature enables ports of a static LACP trunk to operate as individual ports in the absence of proper LACP negotiation with a network peer. Once any one port member hears a LACP PDU from the peer, then all port members of the trunk are bundled to operate as a trunk. This feature is useful for servers with multiple network interfaces using PXE boot.


With this configuration, Netvisor One creates the trunk in the switch, but does not add any of the ports to the trunk. The ports continue to operate individually until LACP PDUs are heard on any of the ports part of the trunk configuration. Once LACP PDUs are sent from the peer for trunk, then all ports of the trunk cease to operate individually and are added to the trunk.


If no LACP PDUs are received for the number of seconds configured as the fallback timeout, Netvisor One LACP checks if LACP negotiation has expired. If LACP negotiation has expired, then ports fall back to individual mode. If LACP negotiation has not expired, another fallback timer is scheduled at a value equal to the fallback timeout.


For example:


  • LACP fallback timeout is set to 50 seconds and LACP negotiation is set to default 90 seconds.
  • After 50 seconds, fallback timer is rescheduled because LACP negotiation has not expired.
  • After an additional 40 seconds (90 total), LACP negotiation expires and become inactive.
  • Another 10 seconds passes (100 seconds total) when the fallback timer expires and the ports fallback to individual ports.


To change the LACP failback mode and timeout, use the new parameters:


CLI (network-admin@switch) > vlag-modify


lacp-mode off|passive|active

Modify the LACP mode.

lacp-timeout slow|fast

Modify the LACP timeout.

lacp-fallback bundle|individua

Modify the LACP fallback.

lacp-fallback-timeout seconds

Modify the LACP fallback timer between 30 and 60 seconds. The default value is 50 seconds.

lacp-port-priority integer 

Configure the LACP port priority as an integer between 1 and 65535.