static routes in network configuration files

[Charles Smith]

Hello,

I would like to establish a static route for my "Ubuntu 10.10" by adding it manually, rather than through the GUI (gnome-nettool).  A network search confirmed that the right place would be /etc/network/interfaces, but there is no stanza in that file for the interface in question, eth0.

Where does Ubuntu store the static routes?

I made a complete copy of /etc and added the route through the GUI, and then compared the new /etc against the old /etc.  There were no changes!

Note that the first mention of eth0 in /var/log/syslog is:
...avahi-daemon[1202]: Joining mDNS multicast group on interface eth0.IPv4 with address w.x.y.z.
avahi-daemon[1202]: New relevant interface eth0.IPv4 for mDNS.
avahi-daemon[1202]: Registering new address record for w.x.y.z on eth0.IPv4.

Does avahi store stuff elsewhere than in /etc?  If so, why?

Any thoughts appreciated.