Change Hostname in Ubuntu

sudo vim /etc/hosts

Change the old hostname to the new one. For example, my /etc/hosts file said

192.168.168.100 oldhostname

So I changed it to

192.168.168.100 newhostname

I also edited the /etc/hostname file.

sudo vim /etc/hostname

It read

oldhostname

So I changed it to

newhostname

After doing the following, the new hostname stuck as required.

sudo /etc/init.d/hostname.sh stop

sudo /etc/init.d/hostname.sh start

And then logout of your shell and log back in.

sudo /etc/init.d/networking restart

You should really read hostname error not resolving for more details.

As for my original problem of not being able to browse the network, it was solved with this fix.