Redirect port with xinetd

UPDATE: This is BAD. It creates an open relay on a secret port! See blog in late 2011 or 2012.

Edit or create a new service in xinetd.

# cat > /etc/xinetd.d/redirect26
service redirect26
{
        port                    = 26
        type                    = UNLISTED
        disable                 = no
        socket_type             = stream
        wait                    = no
        user                    = root
        redirect                = 127.0.0.1 25

Source: http://forum.sw-soft.com/showthread.php?threadid=20949

This is particularly useful with Virtuozzo VPS's because they don't have full IPtables support.

This specific example opens another (non-standard) port for listening to email, which is useful if your ISP is blocking outbound port 25.

"To enable or disable an xinetd service, edit its configuration file in the /etc/xinetd.d directory. If the disable attribute is set to yes, the service is disabled. If the disable attribute is set to no, the service is enabled."