Cisco Fibre Channel Domain Feature and Persistent FC IDs

CE.

The Fibre Channel Domain (FCDomain) feature in Cisco switches provides a mechanism for managing Fibre Channel Identifiers (FCIDs) that are assigned to Fibre Channel (FC) ports. Persistent FC IDs, which are a part of the FCDomain feature, allow for the preservation of FCIDs across switch reboots and port changes. Here are the two statements that are true regarding this feature:

A. If you connect to the switch from a Windows host, be sure to enable the persistent FC ID feature in the VSAN that connects these hosts.

When Windows hosts connect to a Fibre Channel network, they dynamically acquire an FCID, which can change during reboots or zoning changes. This can cause problems with applications that rely on a stable FCID. To solve this problem, the FCDomain feature provides the persistent FC ID feature, which ensures that Windows hosts retain the same FCID across reboots and zoning changes. Therefore, it is essential to enable this feature in the VSAN that connects Windows hosts to the switch.

C. When persistent FC IDs are enabled, FC IDs cannot be changed after a reboot.

Persistent FC IDs are assigned to FC ports based on a predefined naming convention that includes the switch WWN and the port number. When persistent FC IDs are enabled, the FCIDs assigned to the ports are saved in a local database and are preserved across reboots. Therefore, if persistent FC IDs are enabled, FCIDs cannot be changed after a reboot. This feature ensures that applications that rely on a stable FCID can function correctly and that zoning is not affected by changes in FCIDs.

The other answer choices are not true. Here's why:

B. Entries that the switch has learned must be manually acknowledged to be stored in the FCDomain FCID database.

This statement is incorrect. When a switch learns a new FCID, it is automatically added to the FCDomain FCID database. There is no need for manual acknowledgment.

D. A persistent FC ID that is assigned to an F Port cannot be moved across interfaces if the same persistent FC ID is to be maintained.

This statement is incorrect. A persistent FC ID can be moved across interfaces as long as the same persistent FC ID is maintained. This is useful when migrating storage arrays from one interface to another.

E. The current FC IDs in use in the fcdomain are saved across reboots.

This statement is incorrect. When persistent FC IDs are enabled, the FCIDs assigned to the ports are saved in a local database and are preserved across reboots, not the current FC IDs in use in the fcdomain.