FC Domain Parameters

The CCIE DC blueprint lists this as a topic so I need to give it some attention.  I'm not really sure if I understand the scope of what I need to learn, but it can't hurt to start with the 'fcdomain' configuration command.

In the 3.3 version I'm running, these are the options under the fcdomain cmmand:

MDS1(config)# fcdomain ?
  abort                  Flush cached data without commiting and release lock
  allowed                Configure allowed domain IDs
  auto-reconfigure       Configure the autoreconfigure option
  commit                 Commit cached data and release lock
  contiguous-allocation  Configure the contiguous allocation option
  distribute             Enable fabric distribution using CFS
  domain                 Configure the domain id and its type
  fabric-name            Configure the fabric name
  fcid                   Configure fcdomain persistent FCIDs
  optimize               Enable optimized fcdomain behavior
  priority               Configure the priority
  restart                Start a disruptive or non-disruptive reconfiguration
  vsan                   Specify the vsan range

The allowed keyword specifies a simple ordered list
MDS1(config)# fcdomain allowed 1,2,3,239 ?
  ,     Comma
  -     Hyphen
  vsan  Specify the vsan id

The auto-reconfigure keyword performs a disruptive reconfiguration when switches are combined on a fabric that have overlapping domains.
MDS1(config)# fcdomain auto-reconfigure vsan 10

The contiguous-allocation keyword only allows contiguous domain assignment
From the SAN OS guide:
By default, the contiguous domain assignment is disabled. When a subordinate switch requests the
principal switch for two or more domains and the domains are not contiguous, the following cases apply:
• If the contiguous domain assignment is enabled in the principal switch, the principal switch locates
contiguous domains and assigns them to the subordinate switches. If contiguous domains are not
available, the SAN-OS software rejects this request.
• If the contiguous domain assignment is disabled in the principal switch, the principal switch assigns
the available domains to the subordinate switch.
MDS1(config)# fcdomain contiguous-allocation vsan 10

The distribute keyword uses CFS to distribute the allowed domain ID lists in a fabric.
MDS1(config)# fcdomain distribute

 The domain keyword configures the domain ID of the switch. Note that the domain ID's must be unique per VSAN. Using static ID's is recommended. Using preferred ID's can get fairly complex in terms of all the options and outcomes available.  I will test and write about this later.

The fabric-name sets the fabric name that is in the form of a long hex value.
MDS1(config)# fcdomain fabric-name ?
  <hh:hh:hh:hh:hh:hh:hh:hh>  Configure the fabric name value

The fc-id configures a static FCID to a WWN.  When a N or NL ports logs into the MDS, it is assigned a FCID.
MDS1(config)# fcdomain fcid ?
  database    Enter persistent FCIDs submode
  persistent  Enable/disable fcdomain persistent FCIDs
MDS1(config)# fcdomain fcid database

The  optimize keyword allows the selection of either fast or selective restart. 

MDS1(config)# fcdomain optimize ?
  fast-restart       Fast fabric reconfiguration (Fast BF)
  selective-restart  Selective fabric reconfiguration (Selective BF/RCF)

The priority keyword sets how the election of the principal switch in the fabric.  A switch with a lower priority will be elected the principal switch. 128 is the default.
MDS1(config)# fcdomain priority ?
  <1-254>  Specify the priority value

The restart keyword selects if reconfigure fabric (RCF) or build fabric (BF) frames are sent when the domain is started.
MDS1(config)# fcdomain restart ?
  disruptive  Force the disruptive fabric reconfiguration option
  vsan        Specify the vsan range

The vsan keyword specifies if domains are enabled or disabled on the switch
MDS1(config)# fcdomain vsan ?
  <1-4093>  VSAN id range