If you join two fabrics with an inter-switch link, the active zone sets from the two fabrics attempt to merge. The fabrics may consist of a single switch or many switches already connected together. The switches in the two fabrics attempt to create a new active zone set containing the union of each fabric's active zone set. The propagation of zoning information only affects the active zone set, not the configured zone sets.
Zone Merge Failure
If a zone merge is unsuccessful, the inter-switch links between the fabrics will isolate due to a zone merge failure, which will generate an alarm log entry. The reason for the E_Port isolation can also be determined by viewing the port information. Refer to Port Information data window.
A zone merge will fail if the two active zone sets have member zones with identical names that differ in content or type. For example, consider Fabric A and Fabric B each with a zone named “ZN1” in its active zone set. Fabric A "ZN1" contains a member specified by Domain ID 1 and Port 1; Fabric B “ZN1” contains a member specified by Domain ID 1 and Port 2. In this case, the merge will fail and the inter-switch links between the fabrics will isolate.
Zone Merge Failure Recovery
When a zone merge failure occurs, the conflict that caused the failure must be resolved. You can correct a failure due to a zone conflict by deactivating one of the active zone sets or editing the conflicting zones so that their membership is the same. You can deactivate the active zone set on one switch if the active zone set on the other switch accurately defines your zoning needs. If not, you must edit the zone memberships, and reactivate the zone sets. After correcting the zone membership, reset the isolated ports to allow the fabrics to join. Refer to the Resetting a Port procedure.