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Cisco 300-625 DCSAN study materials
Cisco 300-625 DCSAN study resources

Cisco 300-625 DCSAN: Configuring and Managing Fibre Channel Fabrics

Cisco 300-625 DCSAN · Work through your exam, one topic at a time.

All guide sections

Configuring and Managing Fibre Channel Fabrics

Domain 2 tests fabric-wide behaviour: zoning, name service, principal switch and domain management, FSPF, SAN port channels, and inter-VSAN routing. The exam favours scenarios where two switches are physically linked but the fabric will not merge or a zone change does not take effect.

Zoning model

  • A zone contains members: pWWN, fWWN, FC ID, interface, or device alias. A zoneset groups zones. Only an activated zoneset enforces access.
  • The default zone is the policy for devices not in any zone; default is deny unless configured permit.
  • Enhanced zoning distributes the full database and locks changes during distribution; basic zoning distributes only active changes. Pick one mode fabric-wide.
  • Device aliases are fabric services too; commit and distribute them, and keep them consistent across switches.

Fabric services and merge

  • FSPF computes paths; the principal switch assigns domain IDs; FCNS and RSCN support name service and state change notification.
  • An ISL triggers a zoning merge. Merge compares zone members, zone and zoneset names, default-zone policy, enhanced/basic mode and device aliases. A conflict isolates the port.
  • Use show zoneset active, show zone status, show fcdomain and show interface to separate a zone problem from an ISL/domain problem.

Worked example

Two fabrics are joined. The E port becomes isolated. Each switch has a zoneset named PROD and a zone named WEB. On switch A, WEB contains pWWN 21:00:...:A1; on switch B, WEB contains pWWN 21:00:...:B2. Same names, different members: the merge fails. The fix is to make the zone definitions identical, or rename one zone/zoneset, then reactivate and bring the ISL back. If the zone contents differed but names also differed, merge could succeed and both zones would coexist. The reasoning is that names are the merge keys; member differences under the same key are a hard conflict.

Traps

  • Activating a zoneset on only one side of an ISL.
  • Using default-zone permit to hide a zoning mistake, widening access.
  • Mixing enhanced and basic zoning across a merge.
  • Forgetting that zone names and zoneset names are fabric-significant during merge.