Well it has been about a week since I was able to use a Ubuntu 13.04 box and make it a hotspot for wireless. It works great.
So a few remarks.
When hostapd is started it clobbers the IPV6 setup. This is a Kernel bug and an old one see:
of course the developers have not fixed it and sarcastically pointed out that the interface needs to go do down in order for hostpad to enable the features needed for an access point.
But hello it does not clobber IPV4 so I am sorry they are too lazy to fix it. There is a workaround as always, after you start hostapd just add the IPV6 address to your wireless interface. This can be done automatically at rc.local when you boot the machine.
You can run the router virtually. I use VirtualBox of course you need a machine to run VirtualBox with enough resources to run VMs.
But the router does not need that much overhead, if you do not install X then you can get away with 256 MB of memory for the VM.
The you start the VM headless:
“/usr/bin/VBoxManage startvm “VMName” –type headless”.
And remember to allow the USB wireless to be recognized by the host and VM. Then you need to “ifconfig wlan0 down” on the host.
So the setup is fairly general that it you want to use it so the Ubuntu box also acts as your Internet router it can be done. In this case you will need three interfaces, ETH0 to the web, ETH1 to your LAN and WLAN0 for wireless.
The setup should be straight forward but you now need a good IPTABLES configuration since you need to forward packets between the three interfaces.