The confederation identifier. This is an externally visible autonomous system number that identifies the confederation as a whole. This field is only valid if the router is in a confederation. This field must be 0 if and only if the router is not in a confederation. When this field is non zero, the local AS number (bgpRmEntLocalAs) is used within the confederation. If the bgpAsSize is twoOctet, then the range is constrained to be 0-65535. A non-mappable 4-octet AS number should only be used when all BGP speakers within the confederation support 4-octet AS numbers. This field can only be changed when the Admin Status is down.