Ubuntu – Ubuntu Server 12.04.2 – wireless connections


I have used Ubuntu desktop for a while and I'm now trying to set up a server. I'm using a wireless PCI adapter which works fine with Ubuntu Live CD.

On installing the server it found the adapter and (once I had entered the SSID and WPA key) connected to the network almost immediately.
However, after installation on booting for the first time it failed to connect during startup. At this point I'm not sure quite where to go from here. I've read the Server Guide but there is nothing about wireless networking in the networking chapter.

I'm used to the desktop gui so the commandline interface is a bit daunting. Please be gentle …

Just for the record the wireless adapter is a TP-Link TL-WN781ND

My interfaces file looks much simpler –

auto lo
iface lo inet loopback

auto wlan0
iface wlan0 inet dhcp
    wpa-ssid RunnymedeData
    wpa-psk <my_key>

The system won't start the network connection on bootup however it starts almost immediately I set the SSID explicitly on logging in. I don't have to do anything else.
The IP address is correctly assigned by the dhcp server (my router) and the machine then shows in the router's list of connections.
I'll give the static route a try and see how we get on. Back soon.

This problem has to do with the fact that the SSID is hidden on my wireless network. In my view this is a bug.

With SSID hidden : system takes a long time to boot (waiting unsuccessfully for network to start). Once I have logged in then explicitly setting essid with iwconfig enables networking within a few seconds; nothing else needs to be done.

With SSID not hidden : system boots up quickly and networking is immediately up and running.

In summary, nothing to do with the specific adapter and nothing to do with the interfaces file.

Thanks to @chilli555 for taking the time to help.

Best Answer

The usual way to configure a server is to fill in your details in the file /etc/network/interfaces. First, confirm you have a working wireless interface:


Do you have an interface, ideally wlan0? Next confirm it is working as expected:

sudo iwlist wlan0 scan

Do you see your network, among others? If so, edit the file with the editor vim:

sudo vim /etc/network/interfaces

Add your details so it looks something like:

auto lo
iface lo inet loopback

auto wlan0
iface wlan0 inet static  <--you want to be able to reach your server by ssh and ftp
address  <--an address outside the DHCP range in the router
wpa-ssid <your_network>
wpa-psk <your_key>

Save your changes and close vim with :wq. Now get the interface to see and use the new settings:

sudo ifdown wlan0 && sudo ifup wlan0

Confirm you got the new address:


And that you can reach the internet:

ping -c3 www.google.com

Of course, substitute your details above.