I’m attempting to set up a firewall machine. However, packet forwarding does not seem to work. I am running the 2.4.3 kernel on Red Hat Linux 7.0 (the kernel is also from Red Hat).
I have formed a small test network consisting of two Windows machines with the firewall box in between. Both machines can ping the firewall, the firewall can ping either machine, and when the firewall is removed the machines can ping each other.
/proc/sys/net/ipv4/ip_forward contains “1”, as does /proc/sys/net/ipv4/conf/*/forward, and FORWARD_IPV4=”YES”. I have tried downing the firewall (with default ACCEPT on all chains), turning routed on and off, setting the machines on the same and different IP networks, configuring and removing static routes to the two networks, and rebooting all machines. Everything I have found on the Internet has only said “Make sure you echo ‘1’ to /proc/sys/net/ipv4/ip_forward” – which I have done.
I am completely stumped – any suggestions would be greatly appreciated.
