The Wi-Fi Security Blog

Earlier this year, we announced Bonjour Gateway. In the many interviews and customer meetings that followed, I observed that Bonjour is the most widely used protocol that nobody knows. It’s widely used because it’s turned on by default on every Mac, and it’s used in every Apple product to make configuration dead simple.

If you have ever sat at a Mac and done, well, anything, you’ve used Bonjour.

If you have ever seen the Airport Utility pop up when you attach a Mac to an AirPort network, you’ve used Bonjour.

If you’ve ever used AirPlay to do screen mirroring, you’ve used Bonjour.

I could go on, but I won’t. Instead, I’ll shift to the question I’m often asked: “How can I learn more about this protocol?”

First, start by reading Stuart Cheshire’s O’Reilly book, Zero Configuration Networking: The Definitive Guide. Stuart is one of those rare treasures in the networking world. He has spent the last decade doing service discovery and making networking easier, but he is also an incredible writer who can also explain the technology he has created.

After reading Stuart’s book, you’ll be prepared to understand how services are advertised. Install the Bonjour Browser, which you may recognize from our initial Bonjour Gateway demo video. One of the tricky things about using packet captures to learn Bonjour is that it only transmits when it needs to, and depends on endpoints to hold state in a steady-state network. The Bonjour Browser sends queries and tells you what’s out there.  Even better, the Bonjour Browser is also available as a free iOS app, so you can carry troubleshooting in your pocket.  (If you have the iPhone 5, you can even look at Bonjour on both Wi-Fi frequency bands.)

When you have a handle on what the Bonjour Browser is telling you, then you’re ready to dig into packet captures. As with many other network protocols, Ethereal has a dissector to tear apart Bonjour packets. You can concentrate on what the protocol is doing because Ethereal will show you how the fields are put together.

At this point, you’re ready to understand how the Aerohive Bonjour Gateway works.

You can also check out our announcement this week on Free Bonjour Gateway here.