User Level Networking is software designed to
allow the dynamic allocation of IP addresses. The
basic idea is to give different IP addresses to
different users, thus identifying the UID-HOST
pair with an IP address. It includes a patch to
the kernel which must be applied to every client
in the LAN, a suid executable which will be used
by the users to get their IP address from the
server and activate it on a virtual interface
(like eth0:*) on the local computer, and an
executable which will be launched by sshd on the
server host.