My router is set to use DHCP and hands out address in the range 192.168.1.64-255. So to configure a static IP on my LAN, I just set it to an IP which resides outside of this range:
iface eth0 inet static
But since I have to remove this from /etc/network/interfaces in order for network-manager to manage eth0, I no longer have the freedom to configure my IP as static. This is all I meant, I wasn't talking about VPN.
It doesn't really matter since I have no services running on my box, but it is sometimes nice to have a static IP for servers on your LAN. Incidentally, I have another computer under my desk which I use as a file/print server and for running torrents. I gave that a static IP.
Anyway, all is fine. Thanks Andy.
PS: FWIW, If you try to configure eth0 as static through System>Administration>Network, then network-manager will just ignore these settings.
Edit: Of course, I could just set a static IP through /etc/network/interfaces and then network-manager should leave eth0 alone.
Edit again: Apparently not
- "NetworkManager only allows VPN connections if it is currently managing a connection"