V-206665

Discussion

When trunk negotiation is enabled dynamically via features such as Dynamic Trunk Protocol (DTP) or similar, considerable time can be spent negotiating trunk settings (802.1q or ISL) when a node or interface is restored. While this negotiation is happening, traffic is dropped because the link is up from a layer 2 perspective. Packet loss can be eliminated by setting the interface statically to trunk mode, thereby avoiding dynamic trunk protocol negotiation and significantly reducing any outage when restoring a failed link or switch.

Check Content

Review the switch configuration to verify that trunk negotiation is disabled by statically configuring all trunk links. Configuring a command to manually disable negotiation may also be required for some switch platforms.

If trunk negotiation is enabled on any interface, this is a finding.