2.4.2.2 Realms
GNU Radius determines which server a request must be forwarded to by
the request’s authentication realm. There are three kinds of
realms:
- A named realm is the part of a user name following the
at sign (‘@’). For example, if the user name is
‘jsmith@this.net’, then ‘this.net’ is the realm.
The named realms can be cascaded; e.g., a request with user name
‘jsmith@this.net@remote.net’ will first be forwarded to the
RADIUS server of the realm ‘remote.net’, which in turn will
forward it to ‘this.net’.
- A default realm defines the server to which the requests
for realms not mentioned explicitly in the configuration are forwarded.
- An empty realm defines the server to which the requests
without explicitly named realms are forwarded. If the
configuration does not define an empty realm, such requests are
processed by the server itself.
GNU Radius keeps the information about the realms it serves in the
raddb/realms configuration file (see List of Proxy Realms — raddb/realms).