So, I'm setting up a firewall that gets an outside ip address through dhcp and acts as a gateway for an internal network. I had this working on another server, but it started having some problems. I've also had some problems with manually running iptables, so I decided to try shorewall. I got it to mostly work, but there was significant packet loss (>75%). I scrapped it and setup an iptables script. It works for the most part, but it still has some problems. Some connections work at first and then die off, and connecting to the inside ftp server is slow (as well as navigating once inside). Even connecting to an nfs mount from one computer inside the network to another is slow.

The firewall is running Ubuntu 7.07, bind9, dhcpd, and iptables v1.3.6. Here is the iptables script.

#Ignore. Move to the next post.

Let me know if you need any more information.

So, I don't think it's my firewall. I noticed an error that comes up whenever I try to add a second network connection. It doesn't matter if eth0 or eth1 is up first, when I run ifup on the other interface, I get

If both are up, I can't access the internet, but if I run ifdown eth1, the internet works again. I've tried different nics with no difference. I need two since this server is the firewall. Any ideas?