AirServer (http://www.airserver.com) is a great tool for mirroring iOS Devices (iPad, iPhone, iPod etc.) to your Apple Mac or PC. Sadly out of the box it won’t work across VLANs/subnets as it requires Bonjour (mDNS, ZeroConf, what ever you like to call it) to work.
Detailed below is the process that I used to get AirServer working across VLANs and subnets.
Basically there is a free tool named Avahi that will, with minimal tweaking, provide a proxy for Bonjour/mDNS. It doesn’t bridge the subnets together in the way some similar tools do which means you aren’t flooding broadcast traffic across subnets, it simply collects all the information of any Bonjour services and then rebroadcasts them as appropriate.
The basic process requires setting up a linux box (I used Ubuntu 12.04 on a virtual machine within VMWare, but other virtualisation technologies or even a physical box would do), configuring the network interfaces, configuring Avahi and then using AirServer!
Setting up the server
Avahi isn’t very processor or RAM intensive. In my setup I used 1 core and 1GB of RAM, although I suspect it will run fine with a smaller amount of memory. These instructions assume you choose to use Ubuntu, but should be similar for most distributions.
For simplicity’s sake during the intial setup I configured the virtual machine to use a client VLAN and allowed the server to pick up a DHCP address.
Once you’ve ran through the basic install, run the following commands to get up to date and enable SSH.
sudo apt-get update sudo apt-get upgrade sudo apt-get install openssh-server
At this point you can switch across to using an SSH client of your choice (As always I recommend Putty)
Configuring the interfaces
At this point, if you haven’t already done so, you can switch your link to the box to a 802.1q trunk. Depending upon your configuration this may sever your link to the box via SSH so the next section need to be carried out locally.
Use a text editor to edit /etc/network/interfaces, I like nano
sudo nano /etc/network/interfaces
For each VLAN you wish to use Avahi on add the following lines, adjusting as required. The example below configures a virtual interface for VLAN 159 using DHCP for the IP addressing.
auto eth0.159 iface eth0.159 inet dhcp
For the native VLAN you need to configure the physical interface. The below example shows a static IP address assignment for the native VLAN.
iface eth0 inet static address 192.168.3.230 netmask 255.255.252.0
Once you’ve configured all your interfaces restart the network subsystem
sudo /etc/init.d/networking restart
Installing & Configuring Avahi
Simply install Avahi
sudo apt-get install avahi-daemon
To enable the functionality we require open the config file
sudo nano /etc/avahi/avahi-daemon.conf
Find the section
[reflector] #enable-reflector=no #reflect-ipv=no
And change it to
[reflector] enable-reflector=yes #reflect-ipv=no
And then restart the service
sudo /etc/init.d/avahi-daemon restart
And that is pretty much it. if you’ve done everything right you should now be able to connect to your AirServer/Apple TV on one subnet from your iPad/iPhone on another.