Clients can get IP addresses, but not packets

[retrogamer]

I'm working with a Linux router that has a Ethernet NIC connecting to the private network and a modem to connect to the internet. Once I got named running, clients could request DNS information, but couldn't send or receive packets from computers on the internet (pinging didn't work, although they could identify the appropriate IP addresses) Does anybody have an idea of what I did wrong?

[jaboua]

Does the router have a firewall blocking it?

[retrogamer]

There is no firewall. Client computers can do all sorts of other things, ftp, samba file sharing, ssh, but whenever it tries to ask the router to get or send some packets, it does nothing (the client is a winXP box, I just watch the little Networking icon, and i flashes every few seconds, but gets nothing back).

[sheds]

Linux router is just a simple computer so forward packets from one interface to the other, in this case, the modem to the ethernet card. I am running this as well, if i understood correctly, and all i did was enable ip forwarding, assign the ip settings on both cards and the computers inside the private network, get firestarter to perform NAT and that was it.

I don't know if this might help you. Please add some more details as to what you want to achieve so we can help you a bit further.

Good luck.

[retrogamer]

I started the service for IP forwarding; I'm not sure if I have to do device-specific settings for forwarding, though (the Home-Network-mini-HOWTO made it sound kind of like it) although I don't have any firewall stuff set up. Do I need NAT? I'm using slackware 10 if that helps at all....

[retrogamer]

Apparently, IP forwarding does work; just not with the modem. I set my 486's (I'll call it dx4) IP address to 193.168.0.3 and then set one of the router's NICs to 193.168.0.2 and they communicated just great, and other computers could ping it and ssh it through the router (the internal network that dx4 isn't on is 192.168.0.0) So, any ideas as to why the modem won't do forwarding?

[retrogamer]

Ok, I finally got it working; all I needed to do was change rc.modules to start the IP masquerading stuff, then it worked.