If you know anything about my classroom control system that I built, you know that the project requires Bonjour.  This is the technology Apple uses to help you share your music on a network.  Computers discover one another by publishing their address on a multicast port.  Because the port is multicast the information gets sent to all computers on the network (you must have a multicast router).  I used a library in java called Bonaha that abstracted away a lot of the complexities of Apple’s Bonjour SDK.

I wanted a way to do the same thing in .NET because, well frankly I’d like to make my classroom control system a more cohesive piece of software and not the kludge that it is (in 2 different languages Java and .NET and pieced together with Elmer’s Glue©).

The obvious choice to keep up with the network state is Mono.Zeroconf. It’s a project that’s separate from the main Mono repository itself.  I expected this software to work out of the gate.  It may work fine on Linux using the Avahi provider; but with the Bonjour Provider on Windows I had to do some modifications of the source to get it to run.  Luckily there were others online that had already found the problems for me (but the forum posts were in 2 different places and a little difficult to find.), so for your convenience I am combining those bits of information in this blog post.

First you’ll need to do as Frankenspank suggested on this StackOverflow post.  You’ll need to change the UPort Setter in Service.cs file (in the Bonjour Provider Project) to be:

this.port=(ushort)IPAddress.HostToNetworkOrder((short) value);

Next you’ll need to change the OnResolveReply method in the BrowseService.cs file (again in the Bonjour Provider Project).

You’ll need to change the second if statement from

if (AddressProtocol == AddressProtocol.Any ||
    AddressProtocol == AddressProtocol.IPv6)

to

if (AddressProtocol == AddressProtocol.IPv6)