I'm unsure of what's causing my instability but here's what I know:
The server is running Debian with no GUI.
I have a static IP, and /etc/network/interfaces is configured with a 'gateway x.x.x.1' entry.
Periodically, my server loses all internet connectivity, and when I can get to it for access, the default gateway is missing from the routing table.
Because this error halts all traffic to my server, I've set up a cronjob to periodically attempt to 'route add default gw x.x.x.1' so that I don't have to keep physically returning to the machine. I'd like a better solution...
auto lo iface lo inet loopback allow-hotplug eth0 iface eth0 inet static address 192.168.0.121 netmask 255.255.255.0 network 192.168.0.0 broadcast 192.168.0.255 gateway 192.168.0.1 up route add default gw 192.168.0.1 dns-nameservers 192.168.0.1 dns-search domain.com
Why doesn't the entry: up route add default gw x.x.x.1 work in /etc/network/interfaces to keep the gateway in the routing table? Moreover, shouldn't the 'gateway x.x.x.1' entry already make sure that the default gateway stays in the routing table?
Also, what log files should I be looking at in order to track down this reoccurring error?
Side question: could a DoS type attack cause eth0 to go down?