Ad-Hoc Airport Networking

Today, I’m going to sing the praises of the Apple’s rather wonderful Airport Express, the road-warriors best friend. And particularly some of the holes it has helped dig me out of as I travel the world with my fiance. I still have the original with no 802.11n capability, because it has survived 2 laps of the planet and given me no trouble. If it ain’t broke, don’t upgrade it!

In order to support our lifestyle of moving to a new continent every few months whenever our tourist visas expire, we both need to maintain fairly steady internet access to keep our businesses running. That means at least two laptops with internet access at any given time, and often I’d like to have my Aspire One, my Sharp Zaurus and my iPod Touch online too. And preferably on the same subnet, without having to disconnect something else first.

The obvious use for a Airport Express is to use it as a concentrator for all the other devices. Often, a hotel might hand me a single ethernet cable when I check in, or a house I’m renting comes with a single port cable modem — instead of plugging in just my Macbook, the Airport express becomes a shared wireless access point for all of our devices. And even on the occasions where it has taken some cursing and tinkering to have the Express co-operate with some of the peculiar hardware I’ve hooked it up to, it’s nice to know that if I can get my Macbook to connect to a network, it’s a pretty safe bet that I can get the Express to connect too. Eventually.


A little more complicated than that, is when we’re in an airport lounge, or in a building with municipal wifi that forces me to buy a password into the router and sign in through a browser to enable access. If we’re both waiting together, then it’s very straight forward to connect our laptops with an ethernet cable, and sign one of them into the lounge wifi which in turn configures network sharing over ethernet to put the other one online too. I’ve found that manually setting one machine to share from 10.0.2.1 and the other to connect using 10.0.2.2 (with wifi turned off!) avoids half an hour of fiddling with DHCP to have the machines automatically recognise each other.

But even that is not too helpful if I need to sync files between my Aspire One and my Macbook, since even if I buy two passwords, the machines might not be able to see each other anyway. The solution in this case is to have one Mac log into the wifi network, and then configure internet sharing over ethernet just as above. But this time, the ethernet cable then goes into the Airport Express, where it is turned into a wifi access point for the other devices to use. If you do decide to do this, be sure to check the Terms & Conditions of the network provider allow you to indirectly attach a router to their service!!

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