FCID allocation with IVR NAT

Unanswered Question
Mar 9th, 2007

Hi there,

I have just turned on IVR NAT and can see the "virtual" entries in the fcns database for each VSAN. I was surprised to see that it is not a one to one mapping between a "real" domain and a "virtual" domain. I was expecting to see the Domain octet of the FCID translated to a new number that was unique to the VSAN/domain pair the device resided in and the rest of the FCID to remain the same. However, what I see is a unique domain octet for each *VSAN* I am routing to and the rest of the FCID is translated to something that I cannot trace back. Does anybody know how the translation is done? Is there any way of interrogating the mappings held by the switch? fcns output below:

0x070006 N 50:06:04:8c:52:a6:5d:98 (EMC) scsi-fcp:both 253


0x070007 N 50:06:04:84:52:a6:5d:97 (EMC) scsi-fcp:both 253


0x24e164 N 21:01:00:e0:8b:b2:5e:d9 (Qlogic) ipfc scsi-fcp:init


0x24e465 N 21:01:00:e0:8b:b2:6f:dc (Qlogic) ipfc scsi-fcp:init


07 is the local DID on the local VSAN.

24 is one of the IVR'd VSANs, but the first virtual entry seen here is on DID 3 and the second is on DID 5 on the "remote" VSAN. How come the Virtual DIDs aren't different?

Lastly, are the FCID mappings persistent? Could a reload cause a re-allocation of the virtual FCIDs meaning I going to come unstuck if I am IVR-ing using IVR NAT with HPUX/AIX?


I have this problem too.
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a-watkins Tue, 03/20/2007 - 04:00

We found the solution for this in the IVR documentation - the virtual domain IDs are *not* persistent across reloads, so you are at risk of FCIDs changing when using IVR NAT. However, there is a facility to create static pwwn to FCID mappings to solve the problem. The recommendation is to apply persistend FCID mappings for every device in the IVR configuration as well, not just those that would cause problems if the FCID changes. Sounds a lot like hard work to me...


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