Tethering your iPhone : Experiences

Update: Nov. 17th, 2008 - PDANet 1.4.0 allows VPN access, however at first look it doesn’t work correctly with VPN Tracker 5.

One of the biggest benefits of my iPhone that I’ve been waiting vainly to try was the ability to tether my iPhone to my laptop so I could access the net from anywhere in case of an emergency - whether it be a server at work or a life or death flash video that isn’t on YouTube. It’s also very worthwhile to note that this will suck your iPhone’s battery faster than anyone would like - for me it lasts about 2.5 hours as both the WiFi and 3G antennae are in heavy use.

It should be noted that all the present options require jailbreaking your iPhone which is not without its caveats and primarily a reason I want an official solution simply because if Apple breaks the jailbreak during an upgrade you’re forced to wait for the iPhone dev team (it’s amazing the work they’ve done) to be able to get a patch out so they can still jailbreak themselves. The good news on this front is the current jailbreak they have is quite resilient as the current jailbreak method they are using can’t be fixed with software. (Although iTunes 8 does look for jailbroken ipsws and tries to stop them). For more details on the jailbreaking process I recommend checking out the iPhone Dev Team’s Blog

PDANet 1.3.3

By June Fabrics PDA Technology Group
Homepage | Available through Cydia

Pros: * Very easy to use * Very little setup - only need to have the iPhone connect to your laptop’s created wireless network * Keeps working even after the iPhone’s screen has turned off.

Cons: * Does not work with VPN (deal breaker) - IPSec Passthrough does not work * Some Terminal commands do not work - eg. can not ping * Can not use your iPhone for anything else without disrupting connectivity.

Using ssh and SOCKS

Sample Instructions | Requires OpenSSH to be installed on your iPhone
Linked are some instructions on how to do this - I’ve done this before as a poor man’s VPN before so it was straightforward.

Pros: * Easy setup (as OpenSSH is installed by default when jailbreaking now) * Keeps working even after the iPhone’s screen has turned off. Not 100% reliable though. * You can still use your iPhone

Cons: * For those unfamiliar or comfortable with the Terminal it may be a bit confusing. * Does not work with VPN (deal breaker) - IPSec Passthrough does not work

3proxy

Sample Instructions | Available via Cydia

Very similar to simply using the ssh setup - but uses 169.254.x.x and port 1080 for your SOCKS Proxy.

Pros: * It works * Can still use your iPhone

Cons: * Requires more setup (downloading and installing 3proxy). * Requires use of Mobile Terminal. The instructions require force quitting Mobile Terminal, but if you added a & at the end of the command you could then run jobs -p when you want to quit, see the process id and type kill PID (where PID is that number that jobs -p gave you). * Does not work with VPN - IPSec Passthrough does not work

iPhoneModem zsrelay

Homepage | Part a download for OS X (or use PuTTY on Windows) and part iPhone app on Cydia.

Note: There is another iPhoneModem application by Addition that exists that costs $9.99 and as far as I can tell has nothing to offer that the free options here don’t have.

The Mac application side is only required if you’d like to secure the connection between your computer and the iPhone. It will use ssh to secure the connection between the two to start and then puts WEP on the ad-hoc network created as well to help discourage anybody jumping on to the network. (WEP may not be secure but the network I really doubt is going to be around for longer than a brief period of time).

Pros: * Nicest setup * You can still use your iPhone * Secure connection between your computer and the iPhone

Cons: * Harder setup in comparison to other options * Advanced Settings on the iPhone has a download counter that appears to reset whenever you leave that page but updates properly once more data is used. * As with all these options that just use proxies - VPN (IPSec) is not allowed over SOCKS. * Slow setup - and more involved.

NetShare

The original tethering application that was available on the App Store. I opted to not try and install NetShare on my iPhone because even though it’s not publicly available to buy anymore it’s still illegal.

Conclusions

Of the options available iPhoneModem zsrelay is the nicest setup with a good mix of security, ease of use and other features however the easiest to set up and use is hands down PDANet. The unfortunate portion for me is that none of them will allow me to use VPN Tracker to connect to the VPN server at work. Personally I’ll stick with PDANet as it’s the least invasive