XDMCP Direct

When a host attempts to connect to the login server via XDMCP-direct, the host name is compared to the Xaccess entries to determine whether the host is allowed access to the login server. Each Xaccess entry is a host name including the wildcards * (asterisk) and ? (question mark). An * (asterisk) matches zero or more characters and a ? (question mark) matches any one character. An ! (exclamation point) prefacing an entry disallows access, while no preface allows access.

For example, say Xaccess contains the following three entries:

amazon.waterloo.com
 *.dept5.waterloo.com
 !*

The first entry allows access to the login server from host amazon.waterloo.com, the second entry allows access from any host whose full domain name ends in dept5.waterloo.com, and the last entry disallows access from any other host.