Table Of Contents

Configuring Static Domain IDs and Persistent
FC IDs

Configuring Static Domain IDs and Persistent
FC IDs

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The domain manager on the principal switch in a VSAN assigns a domain ID to a switch that is joining the fabric. When a switch boots up or joins a new fabric it can request a specific domain ID or take any available domain ID.

After obtaining the domain ID from the principal switch in the VSAN, the local switch will assign Fibre Channel Identifiers (FC IDs) to each end device as they are logged in to the fabric using a process known as FLOGI (Fabric Login).

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Warning HP-UX and AIX are two operating systems that utilize the FC ID in the device path to the storage. For a switch to always assign the same FC ID to a device, persistent FC IDs and static domain ID must be configured for the VSAN.

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By default, the switch assigns the same FC ID to a device. However, if the switch is rebooted, this database of pwwn/FC ID mapping is not maintained. Enabling persistent FC IDs makes this database persistent across reboots.

In the following procedure, the existing VSAN (3000) has a switch address of xx.xx.xx.xx and a domain ID of 239. This procedure configures a static Domain_ID for a VSAN and enables persistent FC_ID for the same VSAN.

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Step 1 Display the current domain_ID for VSAN 3000 using the command show domain-list.

switch# show fcdomain domain-list vsan 3000

Number of domains: 2

Domain ID WWN

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0xef(239) 2b:b8:00:05:30:00:68:5f [Local] [Principal]

Step 2 Configure the static domain_ID with the domain static command.

switch# conf t 

Enter configuration commands, one per line. End with CNTL/Z. 
switch(config)# fcdomain domain 239 static vsan 3000 

Step 3 Enable persistent FC_ID with fcid persistent.

switch(config)# fcdomain fcid persistent vsan 3000

switch(config)# end 

Step 4 Save the configuration.

switch# copy running-config startup-config

[########################################] 100%

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Note If the domain ID of VSAN 200 is different than what is currently running (22 in this case) then the VSAN has to be restarted before configuration changes to the Domain_ID and FC_ID persistence take effect. Changing Domain_IDs and hence FC_IDs for a device is disruptive because an end device has to relogin to the fabric (FLOGI) to obtain a new FCID.

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Caution Changing Domain_IDs and therefore FC_IDs for a device is disruptive, as an end device has to relogin to the fabric (FLOGI) to obtain a new FCID. However, making a Domain_ID static without changing its value is not disruptive.

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