domain id

[Joe J_1]

Hello,

I have a SAN with a domain id of 10, if I add another fabric the default is 1 who will be the principal switch doman id 10 or 1?

Thanks

[Mohanasundaram_1 · Accepted solution]

Hi Joseph,

If this is added to another fabric, it does not matter.

If it is in the same fabric, the Domain ID of each switch needs to be unique.

With regards,
Mohan.

[Joe J_1]

This new switch is added to the fabric. Will this new switch become the principal?

Joe

[Steven Clementi]

Joseph:

In an earlier posting, it was determined that the switch with the lowest WWID would become the Principal in the case that an election needed to be made. I believe some testing was done to prove this as well.

The role of principal has no bearing on the domain ID or, that is... theDOmain ID has no bearing on who becomes the principal. They mainly serve as unique identifiers within the fabric.


Steven

[SAKET_5]

Hi Joseph,

First, I think you mean you have a SAN switch with domain ID of 10 and if you add another switch the default domain ID value of that switch is 1. So a couple of things:
1. First make sure that you change the domain ID of this switch that you are about to add to a value different from the domain IDs of the existing Fabric switches. Basically, you must have unique domain IDs on all switches that are members of the same fabric.
2. If the switches are in different fabrics and you do not plan to merge them in the future then yes, you can have the same domain IDs for the switches residing in different fabrics.
3. Can you give a reason as to why you are concerned with the selection of Principal switch? I provide the gist of the Prinicipal Switch selection process as below:
- The first switch to be booted up in the fabric is the principal switch of the fabric regardless of any fabric configuration parameters - domain ID, switch wwid, fabricprinicipal enabled/disabled, etc.
- The switch with the lowest wwid becomes the Fabric Principal switch in case of principal switch election scenarios.
- With FOS V4.4.x streams, a new command called "fabricprincipal" allows you to set a preferrence for a switch to become the prinicpal switch in election scenarios. It still can not guarantee your designation.

[SAKET_5]

Sorry Joseph,

a bit more info...

- with "fabricprinicipal" command with "-f" option you can also force a principal switch election - NOTE this forces a fabric reconfiguration which can be disruptive as in data in transmit may be subject to loss!
- generally speaking you would want to enable fabricprincipal preferrence on your core switches by running "fabricprincipal 1" command

Hope, it helps.

[SAKET_5]

oops....and finally the domain id is irrelevant as far as principal switch selection is concerned.