VSAN WWN

[Eranbrown]

For a script I'm building, I need the host to be able to detect if its 2 initiators are connected to the same switch or not. I'm using the switch's WWNN to do that.

Due to a security limitation - the script can't directly query the switch and has to deduce this from the data provided by the switch during login.

My concern is around VSANs, 2 ports in 2 different VSANs are not in the same switch (from the host's perspective).

When creating a new VSAN - does the switch automatically assign the VSAN a new WWNN (I know you can create them using "wwn vsan", I'm asking about the default behavior.

Thanks !!

[Walter Dey]

Why don't you rely on the result of the flogi: the most significant byte of the FC-ID is the domain id, which is a unique identification of the switch.

[Eranbrown]

Thanks for your answer Wdey !

My problem is that (as I understand it) the 2 switches will have different WWNs (and different domain IDs) regardless of whether they are connected with an ISL or not

What I am looking for is to be able to know if the 2 ports are part of the same fabric or not...

Any ideas ?

[Walter Dey · Accepted solution]

Reg. your initial question:

- yes, if you create a new VSAN, a new switch wwn will automatically be created.

- yes, the domain-id per vsan is independent of any ISL. The only requirement in a fabric is the uniqueness of domain-id's per VSAN.

I would configure static domain id's for every vsan and switch; then you can build a table, which domain id belongs to which physical switch.

You script on the host would then use this table, and can make the proper decision.