Domain ID, Front Domain ID, Fabric ID(FID), Backbone Fabric ID

Hi puppan,

Domain ID:
when you connect several fibrechannel switches together they form a so called fabric. Within the fabric each switch is identified by its domainid which has to be unique within this fabric. You can think of the domain id as address of the switch

Fabric ID / Backbone fabric ID:
fibrechannel routers (like mpr7500) can be used to connect multiple fabric together while keeping them logically separated. To identify and distinguish between them the router assigns a fabric id to all connected fabrics (so called edge fabrics). This id is used by the router itself to "know where to route to".
The backbone fabric id is the id of the fabric the router itself belongs to. It doesn't route anything here but behaves like a normal switch.

Front Domain ID:
when connecting a fabric to a router the router presents itself as a virtual switch within this fabric. To be addressable in this fabric the router uses the front domain id. It's pretty much the same like the domain id for switches.

The whole fibrechannel routing concept is maybe not that easy to understand at first glance. Brocade has some very good documentation explaining it.

regards,
bernd