Port forwarding using netcat.

This example shows how to create a custom xinetd service, in this case to forward radmin (port 4899) to another server using netcat.

Create a file in /etc/sysconfig/xinetd.d/ (call it what you want - but for this example radmin would be a good choice)

You also need to ensure that your /etc/services file contains a mapping for the port you wish to forward, e.g. in this case I inserted "radmin 4899/TCP # Remote admin" into my services file - omit the quotes though.

service radmin
{
  flags = REUSE
  protocol = tcp
  socket_type = stream
  port = 4899
  wait = no
  user = nobody
  server = /usr/sbin/nc
  server_args = -w 10 192.168.20.250 4899
  disable = no
}

This will redirect any requests to the local machine on port 4899 to the remote server 192.168.20.250:4899

A poor mans proxy really!