Comment 6 for bug 84537

To Edmunds Kalniņš, Eelko van Breda:

What happens if you just set

 net.ipv4.ip_forward = 1

in /etc/sysctl.conf, and run sysctl -p?

To me, the bug looks like a mistype in default /etc/sysctl.conf (i.e. wrong setting).

Say, here's the relevant section from Fedora 8:
 # Controls IP packet forwarding
 net.ipv4.ip_forward = 0

And this is from Gentoo 2007.0:
 # Disables packet forwarding
 #net.ipv4.ip_forward = 0