I have a laptop with lubuntu 11 with two network interfaces, wireless and wired. Wireless interface connects to the router with DHCP and provides access to the internet. The wired interface has a staic ip address from a different range for internal LAN. I would like to allow computers on the LAN get access to internet using laptop's wireless connection. What are my options here? Do I need a bridge, NAT, firewall?
Lubuntu comes with Network-manager, which makes this very easy. Click on the network icon in your panel, and select Edit connections.
In the dialog that appears, select the wired interface and click Edit. In the IPv4-settings pane in the new dialog, you can select Method: "Shared with other computers". Any internet connection will now be shared on your wired connection, complete with DHCP.