1. System Information & Status

Cisco MDS (NX-OS)

show version

Displays firmware, hardware details, and uptime — used after upgrades or new deployments.

show interface brief

Summarizes Fibre Channel interfaces and states (up/down, speed, port mode).

show flogi database

Shows all devices that have logged in via Fibre Channel — used to verify host and storage visibility.

show zoneset active

Lists currently active zoning configurations (zonesets) per VSAN.

copy running-config startup-config

Saves current configuration to flash memory so it persists after reboot.

Brocade (Fabric OS)

version

Displays Fabric OS version and hardware model.

switchshow

Quick overview of all ports, their online state, speed, and connected devices.

fabricshow

Lists fabric membership (Domain IDs and ISLs) — essential when managing multi-switch fabrics.

portshow 1

Detailed statistics for port 1: WWN, speed, signal quality, and status.

cfgshow

Displays all zones, aliases, and configurations (both defined and active).

Tip: Run switchshow or show interface brief after power-up to confirm all ports and fabrics are operational.

2. Port Configuration Commands

Cisco

conf t
interface fc1/1
  switchport mode F
  switchport vsan 10
  no shut

Explanation:

• switchport mode F — “Fabric” mode for end devices.
• switchport vsan 10 — Assigns port to VSAN 10.
• no shut — Enables the port.

Brocade

portcfgenable 1
portcfgspeed 1,16
portname 1 "ESXi01_HBA1"

Enable, set speed, and name ports before connecting hosts — helps in troubleshooting and documentation.

3. Zoning Configuration

Cisco NX-OS

vsan database
  vsan 10 name PROD_VSAN
zoneset name PROD_ZS vsan 10
  zone name ESXi01_to_VPLEX vsan 10
    member pwwn 20:00:00:25:B5:11:22:33
    member pwwn 20:00:00:25:B5:44:55:66
zoneset activate name PROD_ZS vsan 10

VSANs isolate fabrics, zones define host-to-storage pairs, and zonesets apply configurations.

Brocade (FOS)

alicreate "ESXi01_HBA1","20:00:00:25:B5:11:22:33"
alicreate "VPLEX01_P1","20:00:00:25:B5:44:55:66"
zonecreate "ESXi01_to_VPLEX","ESXi01_HBA1;VPLEX01_P1"
cfgcreate "PROD_CFG","ESXi01_to_VPLEX"
cfgenable "PROD_CFG"
cfgsave

Create aliases for readability, define zones between host and target, and enable the configuration.

4. Fabric and Topology Checks

Cisco

show topology
show fcns database
show vsan
show interface fc1/1

Use these to confirm fabric structure, device registration, and interface health.

Brocade

fabricshow
islshow
switchshow
nsshow

islshow and fabricshow confirm ISL health and fabric membership after adding switches.

5. Diagnostic & Troubleshooting Commands

Cisco MDS Diagnostics

show interface fc1/1 counters
show interface fc1/1 details
show flogi database
show zoneset active vsan 10
show logging log
show tech-support details
show interface transceiver details

• show interface counters — Check CRC, drops, or frame loss.
• show flogi database — Confirm device logins.
• show logging log — Review link resets and events.
• show tech-support — Full diagnostic bundle for TAC.

Brocade FOS Diagnostics

porterrshow
portshow 1
errdump
fabriclog --show
portlogdump 1
supportsave

• porterrshow — Primary command for CRC and signal issues.
• errdump — Live system event feed.
• supportsave — Collect logs for Broadcom Support.

Typical Troubleshooting Flow:

1. switchshow or show interface brief – verify ports are online.
2. nsshow or show flogi database – confirm devices logged in.
3. porterrshow or show interface counters – look for CRC or timeout errors.
4. islshow or show topology – check ISL stability.
5. supportsave or show tech-support – collect logs for vendor support.

6. Backup and Restore

Cisco

copy running-config startup-config
copy running-config tftp:

Brocade

configupload
configdownload
supportsave

Always back up configurations before firmware upgrades or zoning changes.

7. Quick Reference Summary

8. Real-World Diagnostic Flow

If a host loses access to storage:

1. Check visibility:
   • Cisco: show flogi database
   • Brocade: nsshow
2. Verify zoning:
   • Cisco: show zoneset active
   • Brocade: cfgshow
3. Inspect physical links:
   • Cisco: show interface fc1/1 counters
   • Brocade: porterrshow
4. Check ISLs (if multi-switch fabric):
   • Cisco: show topology
   • Brocade: islshow
5. Collect logs:
   • Cisco: show logging log / show tech-support
   • Brocade: errdump / supportsave

9. Conclusion

Both Cisco and Brocade offer stable, enterprise-grade Fibre Channel switching. Cisco NX-OS appeals to network engineers familiar with IOS, while Brocade FOS favors storage admins with its concise syntax.

For best practice:

• Use consistent naming for ports and zones (e.g., Host_HBA1, VPLEX_PortA).
• Run diagnostics like porterrshow or show interface counters regularly.
• Back up configurations before making any changes.

Mastering these commands makes SAN management predictable, fast, and far easier to troubleshoot — whether your environment runs on Cisco, Brocade, or both.