The configured Domain_ID of the particular switch on this Fabric, or zero if no Domain_ID has been configured. The meaning of this object depends on t11FamConfigDomainIdType object. If t11FamConfigDomainIdType is 'preferred', then the configured Domain_ID is called the 'preferred Domain_ID'. Valid values are between 0 and 239. In a situation where this Domain_ID cannot be assigned, any other Domain_ID will be acceptable. A value of zero means any Domain_ID. If t11FamConfigDomainIdType is 'insistent', then the configured Domain_ID is called the 'insistent Domain_ID' and valid values are between 1 and 239. In a situation where this Domain_ID cannot be assigned, no other Domain_ID is acceptable. In both of the above cases, the switch sends an RDI (Request Domain_ID) to request this Domain_ID to the Principal Switch. If no Domain_ID is able to be granted in the case of 'preferred', or if an 'insistent' Domain_ID is configured but not able to be granted, then it is an error condition. When this error occurs, the switch will continue as if it receives a SW_RJT with a reason/explanation of 'Unable to perform command request'/'Domain_ID not available'. That is, its E_Ports on that Fabric will be isolated and the administrator informed via a 't11FamDomainIdNotAssigned' notification. If t11FamConfigDomainIdType is 'static', then the configured Domain_ID is called the 'static Domain_ID' and valid values are between 1 and 239. In this situation, there is no Principal Switch in the Fabric and the Domain_ID is simply assigned by configuration, together with the Fabric_Name. A switch configured with a static Domain_ID, on receiving an EFP, BF, RCF, DIA, or RDI SW_ILS, shall reply with an SW_RJT having Reason Code Explanation 'E_Port is Isolated' and shall isolate the receiving E_Port. For the persistence of values across reboots, see the MODULE-IDENTITY's DESCRIPTION clause.