My home server seems to have developed a problem where its internal-facing network card “jams up”. It still keeps its IP address and everything looks normal, but in actual fact no traffic passes through it, cutting all my LAN hosts off from the Internet.
Restarting iptables, network services or anything else doesn’t help. The only cure I’ve found is to reboot the whole box.
This is OK if I’m using the computer at the time, but a pain if it breaks overnight or while I’m out, as things like my folding@home client, Vista Media Centre TV listings and overnight BitTorrent downloads need Internet access.
So I wrote this bash script to periodically check if it’s broken, and reboot if it is. The only gotcha is that it tests if the interface is working by pinging another LAN host. This is by no means a concrete test!
if ! ping -c 1 -w 5 "$HOST" &>/dev/null ; then
logger ZEUS REBOOT