I have two computers (let say "A" and "B") that are already pinging and sshing each other via firewire, both with static ip. Computer A is connected to the Internet and I want it to share its internet connection to computer B. I have no idea of how this can be done via firewire interface. Any ideas? thanks a lot.

1 Answer 1


Computer [A]:

  • enable IP forwarding
    • temporarily by running echo 1 > /proc/sys/net/ipv4/ip_forward
    • or permanently by adding net.ipv4.ip_forward=1 in /etc/sysctl.conf
  • iptables rules, assuming eth0 is your interface to the internet and firewire0 the internal connection to comp [B] (to make them permanent, add them to /etc/rc.local before the "exit 0":

/sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE /sbin/iptables -A FORWARD -i eth0 -o firewire0 -m state --state RELATED,ESTABLISHED -j ACCEPT /sbin/iptables -A FORWARD -i firewire0 -o eth0 -j ACCEPT

Computer [B]:

  • check for a valid DNS server in /etc/resolv.conf, if not add a line with nameserver
  • make sure the default route is through comp [A] (route -n shows computer [A] IP's on the line with destination if not, run route del default; route add default gw COMPUTER_A_IP_ON_firewire0

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