Trunk group operation using the trunk option

This method creates a trunk group that operates independently of specific trunking protocols and does not use a protocol exchange with the device on the other end of the trunk. With this choice, the switch simply uses the SA/DA method of distributing outbound traffic across the trunked ports without regard for how that traffic is handled by the device at the other end of the trunked links. Similarly, the switch handles incoming traffic from the trunked links as if it were from a trunked source.

When a trunk group is configured with the trunk option, the switch automatically sets the trunk to a priority of "4" for Spanning Tree operation (even if Spanning Tree is currently disabled). This appears in the running-config file as spanning-tree Trkn priority 4. Executing write memory after configuring the trunk places the same entry in the startup-config file.

Use the trunk option to establish a trunk group between a switch and another device, where the other device's trunking operation fails to operate properly with LACP Link Aggregation Control Protocol. IEEE standard that allows to combine several physical ethernet links in network devices to form a single logical link. trunking configured on the switches.