Port Trunking

CLI: Viewing and Configuring Port Trunk Groups

Switch “A” with ports set to LACP passive.

Switch “A” with ports set to LACP active.

Switch “B” with ports set to LACP passive.

Dynamic LACP trunk cannot automatically form because both ends of the links are LACP passive.

(In this case spanning-tree blocking is needed to prevent a loop.

Switch “B” with ports set to LACP passive.

Dynamic LACP trunk automatically forms because both ends of the links are LACP and at least one end is LACP active. (Spanning tree is not needed, and the clear advantages are increased bandwidth and fault-tolerance.)

Figure 12-10. Example of Criteria for Automatically Forming a Dynamic LACP Trunk

Syntax: interface < port-list > lacp active

Configures < port-list > as LACP active. If the ports at the other end of the links on < port-list > are configured as LACP passive, then this command enables a dynamic LACP trunk group on < port-list >.

This example uses ports C4 and C5 to enable a dynamic LACP trunk group.

ProCurve(config)# interface c4-c5 lacp active

Removing Ports from an Dynamic LACP Trunk Group. To remove a port from dynamic LACP trunk operation, you must turn off LACP on the port. (On a port in an operating, dynamic LACP trunk, you cannot change between LACP Active and LACP passive without first removing LACP operation from the port.)

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