Description:

The X firewall proxy (xfwp) is an application layer gateway proxy that
may be run on a network firewall host to forward X traffic across the
firewall. Used in conjunction with the X server Security extension and
authorization checking, xfwp constitutes a safe, simple, and reliable
mechanism both to hide the addresses of X servers located on the
Intranet and to enforce a server connection policy. Xfwp cannot pro-
tect against mischief originating on the Intranet; however, when prop-
erly configured it can guarantee that only trusted clients originating
on authorized external Internet hosts will be allowed inbound access to
local X servers.