The Scope ID is a character string which is appended to the NetBIOS name for all NetBIOS over TCP/IP communications. It provides a method to isolate a collection of computers that only communicate with each other.
If you logon to a domain, only a domain controller with the same Scope ID will be able to validate the logon.
Scope ID is case sensitive.
Non-NetBIOS communication, like PING, does not use the Scope ID, but a NET VIEW to a computer with a different Scope ID will result in an error 53.
See knowledge base article Q119493.