[y011]

A colleague and I were updating to 3.0 the other day and he immediately tried out tethering since our carrier here in Australia hasn't locked that down. It worked and the way he described it working sounded to me like:

* iphone is presented as some kind of USB ethernet device to Mac
* DHCP server runs on iphone to give iphone fake usb ethernet interface a TCP/IP address
* phone NATs mac's connection made over it to 3G

This would mean that there's a little IP network between the iphone's "ethernet" interface on the mac and the iPhone.

hearing that my first thought, literally, was wondering if the omnifocus on the iphone's Bonjour advertisement I'd normally see over wifi would be visible to the mac when the phone was in this mode.

Finally had a look today - yep it is. Once I make tethering available it's just another interface with an IP address on the iPhone and the multicast Bonjour advertisements are emitted on all interfaces including the one "facing" the mac over the USB. So I can now sync when I'm onsite and have no super secure wifi network to use.

20:10:28.259587 IP 192.168.20.1.5353 > 224.0.0.251.5353: 0 [2a] PTR (QM)? _ofocus-sync._tcp.local. (107)

That's omnifocus on the iPhone making itself discoverable by the mac via Bonjour. From there it finds the bonjour advertisement for the sync server it's looking for and it syncs. That simple.

In the past my options when I'm onsite (away from my networks :-) were to use .Mac or to run an adhoc wifi network on my mac and connect over that. Both those options scare me (.Mac is asking for it and an adhoc networks only support busted-since-2001 WEP).

So this working over tethering is pretty win.

I'd imagine the same will be the case with Internet Tethering and bluetooth assuming BT tethering presents itself to the mac as a network bluetooth profile or a dial-up-networking profile. I haven't checked that yet.

Basically if you run 3.0 and your carrier isn't super evil you can use this to sync omnifocus to your phone.

Even if they don't permit tethering (AT&T) maybe those carrier settings applied with 3.0 don't entirely hide the Internet tethering function. So you may still be able to enable this link between the phone and the Mac. Worth checking.

y011