A domain ID conflict is detected on a switch. Which action resolves the issue in the shortest possible time after the preferred domain ID is changed to a static domain ID?

When a domain ID conflict occurs, the fabric is already segmented, and traffic across the conflicting switches is disrupted. After configuring a new, unique static domain ID, the change must be applied. An fcdomain disruptive restart is the most direct and fastest method to force the switch to adopt the new configuration. This command immediately brings down the Inter-Switch Links (ISLs), forces a fabric reconfiguration, and allows the switch to join the fabric with its new, non-conflicting domain ID. This clean-slate approach ensures the quickest resolution in an already unstable fabric state.

B. Issue an fcdomain nondisruptive restart. A non-disruptive restart is intended for planned changes in a stable fabric and may fail or take longer to converge in a conflict-induced unstable state.
C. Enter the commands for a VSAN suspend / no-suspend. Suspending and re-enabling an entire VSAN is a far more impactful and time-consuming operation than restarting a single process, making it inefficient for this specific issue.
D. Enter the commands to complete a domain manager fast restart. This is not a standard, documented Cisco MDS command. The correct command syntax for restarting the domain manager process is fcdomain restart.

1. Cisco MDS 9000 Series Fabric Configuration Guide, NX-OS Release 8.x, "Configuring Domain Parameters" section.

Reference: In the subsection "Restarting the Domain Merge Process," the guide describes the fcdomain restart command. It explains that a disruptive restart forces the local switch to reacquire a domain ID, which is necessary to apply a new static ID in a conflict scenario. The disruptive nature is acceptable as the fabric is already segmented.

2. Cisco MDS 9000 Series Command Reference, NX-OS Release 8.x, fcdomain restart command description.

Reference: The documentation for the fcdomain restart disruptive command specifies that it forces a reconfiguration of the fabric by taking the E ports offline and then bringing them back online. This forced re-initialization is the most expedient way to resolve a domain ID conflict after correcting the configuration.

3. Cisco MDS 9000 Series Troubleshooting Guide, "Troubleshooting Fibre Channel Domain and Fabric Merge Issues" chapter.

Reference: This guide details the steps for resolving domain ID conflicts. The procedure involves identifying the conflict, assigning a unique static domain ID to one of the switches, and then executing an fcdomain restart disruptive on that switch to force it to rejoin the fabric with the new ID.