The ifconfig -a shows some info that ipconfig/all doesn't. OTOH, it still doesn't show me (on SuSE 7.3) things like gateway, dns, dhcp, which ipconfig/all shows in Windows.
The route command, with no arguments, shows me my default gateway. Using "netstat -nr" does the same. I can "cat /etc/resolv.conf" to see the nameservers that I've set up.
I'm not sure if there's one command to show all these (ip, gateway, dns) from a linux command line.