FCID ? how is calculed

[jjpeyrache]

hi

where can i get information regarding FCID number

0XYYYYYY ?

where is coming/derived from ?

is it really unique or can i get issue when

merging fabric ?

any advice will be welcomed

thanks

JYP

[tblancha]

Actually, the FCID can be broken down like this- 0xXXYYZZ. The XX is the domain number which is randomly determined or assigned if in a merged fabric. This number can run between 1 and 127. The YY is the area. Usually, the area number represents which physical port this is but not necessarily. The ZZ is the port number and is now usually 00 in a MDS situation and since most devices are now N ports and not loop devices. If this is loop port, there can be multiple addresses in this last byte.

In a merged fabric, if two switches are setup with the same domain ID, the (T)E port will isolate since you cannot have two switches with the same domain ID. Else, a principal switch will be elected and the non-principal switch will request and be assigned a domain ID.

[jjpeyrache]

thanks for your reply can you explain let bit better some sentences

"Usually, the area number represents which physical port this is but not necessarily"

if not physical port what it will be ?

what are loop devices ?

thanks

JYP

[tblancha · Accepted solution]

If it is not the physical port, then it can be anything. Say the domain is 0x12, then alot of times, the address assigned on the first port will be 0x120000, then the 2nd port would get 0x120100, etc. But this is not a requirement.

Arbitrated Loop is a type of topology for fibre channel.

[abdulhakam]

Hi Sorry,

Can help me the ZZ refer to port number ? If Cisco MDS got 18 port how the fcid should be present?

vsan 1 wwn 50:00:07:63:04:08:56:XX fcid 0x2f0000 dynamic
vsan 1 wwn 10:00:00:3A:6a:ae:e2:XX fcid 0x2f0001 dynamic
vsan 1 wwn 50:05:07:PP:04:10:96:XX fcid 0x2f0002 dynamic

It should be like this ? 00 refer to Port 1, 01 Refer to Port 2, 02 Refer to Port 3 ?

TQ