Internet Sharing From iMac To MacBook With Port Forwarding?

[Darkroom]

i am WELL lost!

my situation: i don't have a wireless router. i have a DSL modem connected to my iMac via ethernet running Leopard. on my iMac i turn on "Internet Sharing" (with password protected airport options) so that i can access the internet using my iPod Touch and Nintendo Wii.

i just bought a MacBook that i can also use on this network. however, i can only "surf the web" since my iMac's built-in AirPort card is only forwarding TCP ports 80 and 443. but i need to forward these ports:

1. iChat = TCP 5298, 5190-5200
2. FTP = TCP 20-21

apparently suffering from a "Double NAT"(??) as my MacBook's automatically assigned IP is 10.0.2.5.

how can i forward these ports?

 

[LANz]

I remember doing something similar but not having that problem, could it be because the Firewall on the "host" computer is on?!?

i am WELL lost!

my situation: i don't have a wireless router. i have a DSL modem connected to my iMac via ethernet running Leopard. on my iMac i turn on "Internet Sharing" (with password protected airport options) so that i can access the internet using my iPod Touch and Nintendo Wii.

i just bought a MacBook that i can also use on this network. however, i can only "surf the web" since my iMac's built-in AirPort card is only forwarding TCP ports 80 and 443. but i need to forward these ports:

1. iChat = TCP 5298, 5190-5200
2. FTP = TCP 20-21

apparently suffering from a "Double NAT"(??) as my MacBook's automatically assigned IP is 10.0.2.5.

how can i forward these ports?

 

[Darkroom]

nope, the iMac that is sharing it's internet over AirPort is set to allow all incoming connections.