About Cisco Trunking | Zoning | Virtual SAN - SAN Admin - A Guide to Storage & Backup Administrators

ISL TRUNKING

Preface

When you allow two Cisco MDS switches to merge zone information after each already has zoning information, and an Extended Inter-Switch Link Protocol (EISL) link is configured between them.

ISL Trunking between 2 Cisco mds Switches

Requirements

Cisco recommends that you have knowledge of these topics:

Zoning configuration on the Cisco MDS 9000 series switches

Cabling and configuration of an (E)ISL trunk between Cisco MDS 9000 switches

Best Practices

When a zone merge occurs, as long as there is not competing information, each switch learns the others zones. Each switch then has three configuration entities. The switches have:

The saved configuration in NVRAM

This is the configuration as it was the last time the copy running-configuration startup-configuration command was issued.

The running configuration

This represents the configuration brought into memory upon the last time the MDS was brought up, plus any changes that have been made to the configuration. With reference to the zoning information, the running configuration represents the configurable database, known as the full database.

The configured zoning information from the running configuration plus the zoning information learned from the zone merge. This combination of configured and learned zone information is the active zoneset.

When an MDS is booted, it comes up with the configuration previously saved in NVRAM. If you configured the switch after configuration was loaded from NVRAM, there is a difference between the bootup and running configuration until the running configuration is saved to the startup configuration.

This can be likened to having a file on the local hard drive of your PC. The file is saved and static, but if you open the file and edit, there exists a difference between the changed file and the file that still exists on saved storage. Only when you save the changes, does the saved entity represent the changes made to the file.

Example

You have two standalone MDS switches, already in place and each with their own configured zone and zoneset information. Switch A has an active zoneset known as zoneset 1, and Switch B has an active zoneset known as zoneset 2. Within zoneset 1 on Switch 1 is zone A, and on Switch B, zoneset 2 has member zone B.

When an ISL link is created between these two switches, each sends their zoneset which includes their zone information to the other switch. On a merge, the switch selects the zoneset name with the higher ASCII value and then merges their zone member. After the merge, both switches have a zoneset name zoneset 2 with zone member zone 1 and zone 2.

Create zone and zoneset. Activate on Switch A.

SwitchA# config t

Enter configuration commands, one per line. End with CNTL/Z.

SwitchA (config)# vsan database

SwitchA (config-vsan-db)# vsan 100

SwitchA (config-vsan-db)# exit

SwitchA (config)# zone name zoneA vsan 100

SwitchA (config-zone)# member pwwn 11:11:11:11:11:11:11:1a

SwitchA (config-zone)# member pwwn 11:11:11:11:11:11:11:1b

SwitchA (config-zone)# exit

SwitchA (config)# zoneset name zoneset1 vsan 100

SwitchA (config-zoneset)# member zoneA

SwitchA (config-zoneset)# exit

SwitchA (config)# zoneset activate name zoneset1 vsan 100

Zoneset activation initiated. Check the zone status

SwitchA (config)# exit

SwitchA# sh zoneset active vsan 100

zoneset name zoneset1 vsan 100

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:12b

SwitchA#

Create zone and zoneset. Activate on Switch B.

SwitchB# config t

Enter configuration commands, one per line. End with CNTL/Z.

SwitchB (config)# vsan database

SwitchB (config-vsan-db)# vsan 100

SwitchB (config-vsan-db)# exit

SwitchB (config)# zone name zoneB vsan 100

SwitchB (config-zone)# member pwwn 22:22:22:22:22:22:22:2a

SwitchB (config-zone)# member pwwn 22:22:22:22:22:22:22:2b

SwitchB (config-zone)# exit

SwitchB (config)# zoneset name zoneset2 vsan 100

SwitchB (config-zoneset)# member zoneB

SwitchB (config-zoneset)# exit

SwitchB (config)# zoneset activate name zoneset2 vsan 100

Zoneset activation initiated. Check the zone status

SwitchB (config)# exit

SwitchB# sh zoneset active vsan 100

zoneset name zoneset2 vsan 100

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:22

pwwn 22:22:22:22:22:22:22:2b

SwitchB#

Now, bring up an ISL link between the switches and allow the zoning information to merge.

Bring ISL link up and verify zone merge on Switch A.

SwitchA# config t

Enter configuration commands, one per line. End with CNTL/Z.

SwitchA (config)# int fc1/5

SwitchA (config-if)# no shut

SwitchA (config-if)# exit

SwitchA (config)# exit

Note: Make sure VSAN 100 is allowed on ISL.

SwitchA# sh zoneset active vsan 100

zoneset name zoneset2 vsan 100

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

SwitchA# sh zoneset vsan 100

zoneset name zoneset1 vsan 100

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

Bring ISL link up and verify zone merge on Switch B.

SwitchB# config t

Enter configuration commands, one per line. End with CNTL/Z.

SwitchB (config)# int fc2/5

SwitchB (config-if)# no shut

SwitchB (config-if)# exit

SwitchB (config)# exit

SwitchB# sh zoneset active vsan 100

zoneset name zoneset2 vsan 100

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

SwitchB# sh zoneset vsan 100

zoneset name zoneset2 vsan 100

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

Notice that after the zone merges, the active zoneset name is zoneset2 on both switches. A = 65 and B = 66 in decimal. For more information about the ASCII table, refer to ASCII Table and Description.

In order to avoid future zoneset activation problems, the zone copy active-zoneset full-zoneset vsan 100 command should be issued at this point on the switch. First, examine if the command is issued, and how the new zoning information is handled. When the zone copy command is issued, it adds the learned zone information, zone B in this case, to the running configuration. If zone B has not been copied from residing in memory to copied into the running configuration, zone B information is not pushed back out.

Note: The zone copy command deletes all fcalias configuration.

Running Configuration of Switch A

Before the zone copy active-zoneset full-zoneset vsan 100 command is issued:

SwitchA# sh run | b "Active Zone Database Section for vsan 100"

!Active Zone Database Section for vsan 100

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

zoneset name zoneset2 vsan 100

member zoneA

member zoneB

zoneset activate name zoneset2 vsan 100

do clear zone database vsan 100

!Full Zone Database Section for vsan 100

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

zoneset name zoneset1 vsan 100

member zoneA

After the zone copy active-zoneset full-zoneset vsan 100 command is issued:

SwitchA# zone copy active-zoneset full-zoneset vsan 100

WARNING: This command may overwrite common zones in the full zoneset. Do you want to continue? (y/n) [n] y

SwitchA# sh run | b "Active Zone Database Section for vsan 100"

!Active Zone Database Section for vsan 100

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

zoneset name zoneset2 vsan 100

member zoneA

member zoneB

zoneset activate name zoneset2 vsan 100

do clear zone database vsan 100

!Full Zone Database Section for vsan 100

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

zoneset name zoneset1 vsan 100

member zoneA

zoneset name zoneset2 vsan 100

member zoneA

member zoneB

Running Configuration of Switch2

Before the zone copy active-zoneset full-zoneset vsan 100 command is entered:

SwitchB# sh run | b "Active Zone Database Section for vsan 100"

!Active Zone Database Section for vsan 100

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

zoneset name zoneset2 vsan 100

member zoneB

member zoneA

zoneset activate name zoneset2 vsan 100

do clear zone database vsan 100

!Full Zone Database Section for vsan 100

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

zoneset name zoneset2 vsan 100

member zoneB

After the zone copy active-zoneset full-zoneset vsan 100 command is entered:

SwitchB# zone copy active-zoneset full-zoneset vsan 100

WARNING: This command may overwrite common zones in the full zoneset. Do you want to continue? (y/n) [n] y

SwitchB# sh run | b "Active Zone Database Section for vsan 100"

!Active Zone Database Section for vsan 100

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

zoneset name zoneset2 vsan 100

member zoneB

member zoneA

zoneset activate name zoneset2 vsan 100

do clear zone database vsan 100

!Full Zone Database Section for vsan 100

zone name zoneB vsan 100

pwwn 22:22:22:22:22:22:22:2a

pwwn 22:22:22:22:22:22:22:2b

zone name zoneA vsan 100

pwwn 11:11:11:11:11:11:11:1a

pwwn 11:11:11:11:11:11:11:1b

zoneset name zoneset2 vsan 100

member zoneB

member zoneA

In reference back to the three entities of configuration, they are as follows on zone A before the zone merge:

Saved configuration: nothing since zone information has not been saved by issuing the copy run start command.

Running configuration: consists of zone A.

Configured and learned information: consists of zone A.

After the zone merge, the entities are:

Saved configuration: nothing has been saved.

Running configuration: consists of zone A.

Configured and learned information: consists of zone A and zone B.

Zone B has not become part of the running configuration. Zone B has been learned, and is in the active zoneset. Only when the zone copy active-zoneset full-zoneset vsan 100 command is issued, zone B becomes copied from being learned to added to the running configuration. The configuration looks as follows after the command is issued:

Caution: The zone copy command deletes all fcalias configuration.

Saved configuration: nothing has been saved.

Running configuration: consists of zone A and zone B.

Configured and learned information: consists of zone A and zone B.

Commands

By default, the zone in basic mode distributes the active zoneset database only; this command was introduced in 1.0.4. SAN-OS propagates the active zoneset and full zoneset database:

zoneset distribute full vsan <vsan_id>

This command must be explicitly enabled on each Virtual Storage Area Network (VSAN) on every switch, if the zone update or zoneset activation will be completed on any switch in the fabric with basic zoning. This eliminates the need to do a zone copy prior to zoning changes completed on any switch in the fabric. It is still necessary, however, to issue the copy running start command in order to save to full zoneset in NVRAM prior to rebooting the switch. This command is not necessary on zone in enhance mode as it distributes the active zoneset and full zoneset database automatically after zoneset activation.