Hi,

I did it. :)

As m0n0 is now doing the PPPoE authentication, WAN will be ng0.  There 
is no way to set the map for xl1 in the webGUI.

I did it through webGUI's exec.php

   1. 192.168.0.0/24 is my LAN, 192.168.0.254 is m0n0's LAN interface
      ip, 10.0.0.138 is my modem's ip.
   2. I create the following lines in a file (unix format), say
      xl1.rules, on my PC.
          * map xl1 from 192.168.0.0/24 to 10.0.0.138/32 -> 10.0.0.1/32
            proxy port ftp ftp/tcp
          * map xl1 from 192.168.0.0/24 to 10.0.0.138/32 -> 10.0.0.1/32
            portmap tcp/udp auto
          * map xl1 from 192.168.0.0/24 to 10.0.0.138/32 -> 10.0.0.1/32
   3. Copy the file to a msdos formated floppy.
   4. On the m0n0 webGUI, type url http://192.168.0.254/exec.php
   5. Execute the command ifconfig xl1 inet 10.0.0.1/24 alias
   6. Insert the created floppy
   7. Execute the command mount -t msdos /dev/fd0 /mnt/
   8. Execute the command ipnat -f /mnt/xl1.rules

Now I can telnet and browse to the modem using the ip address 10.0.0.138.

Cheers
Raylund