I use a software called connecity ( http://connectify.me/ ) to turn my laptop to a wifi router and provide other devices with internet using my DSL connection. But after i switched to the ubuntu 11.10 I can't do this thing. Is there any linux software or trick available to do this?
yes, Ubuntu and many other Linux distributions contain a feature called "ad-hoc network" and "wifi tethering"
You can create an adhoc wifi and make near clients to access your network.
For this, you need some connection (cable connection, or another wifi connection but with a second wifi adapter).
Remember, you can't use the same adapter as WiFi receiver and wifi spot.
You go to network settings ->
You create a connection and select
you can specify a password and enjoy.
there is bug currently in Ubuntu so there is work around for making ad hoc wifi access point, queting bellow:
"connecting with shared with other computers connection in NetworkManager. Other computer gets IP but NetworkManager disconnects the shared connection after half a second. This same setup worked perfectly fine in 11.04. Is there any fix, workaround or alternative way to share a connection with another computer over an Ethernet cable. (I can downgrade to 11.04 but I'd rather not ).
EDIT: found a workaround The workaround for now is to set IPv6 options to Ignore and then sudo killall dnsmasq. Reconnect and it should work."
I done in on my laptop with Ubuntu 12.04 and mine working fine now.