How Mac OS X’s “Internet Sharing” Saved My Vacation

So I am on vacation right now and the unthinkable happened after we checked into our place: there was NO wifi available. The hotel didn’t have wifi available at all (welcome to 1990). No coffee shops or residences in the area where I could see their network. Not a thing.

Luckily my dad has a Sprint EVDO card that he uses to get online with his MacBook, but I didn’t want to have to depend on using his computer during our whole trip. I got to thinking about how we could share his connection and immediately fired up the “Internet Sharing” functionality that is available in Mac OS X.

I flipped open the “Internet Sharing” preference pane, selected to share his EVDO connection through Airport and immediately went to my machine. I saw the new network that was created, immediately connected to the network (thinking “how easy was this?) and… nothing.

System Preferences - TCP/IP SettingsI went back into the Network Preference Pane on my computer and saw that while I was connected to my dad’s “Airport Network”, I was not getting a real IP address (getting one of those nasty 169.x.x.x self-assigned addresses). Those are no fun to deal with ever and was thinking “now what?”.

After poking around the network configuration on my dad’s computer, I finally saw that he too had a self-assigned IP address for his Airport. It turns out that the Sprint EVDO card actually uses PPP to connect and there’s no real place to specify an IP address. I decided to flip back to the configuration of his Airport and give him a hard-coded IP address (opting with the ever popular 192.168.1.1). From there I went back to my computer and gave myself a hard-coded IP address (going with the next logical address of 192.168.1.2). I added my dad’s IP of 192.168.1.1 for the Router field within the preference pane and then… nothing.

System Preferences - DNS SettingsSo now I was getting frustrated and just out of pure frustration, I fired up Terminal and tried to ping my dad’s computer. No problems… Ok, cool. Now for kicks I decided to ping the IP address of the Router that gets populated when he connects through EVDO. Guess what? I was hitting it! It was all coming together now. I had Internet connectivity, I just didn’t have any DNS configured.

I quickly fired up OpenDNS.com (on my dad’s computer, remember I still couldn’t resolve URLs), got the two OpenDNS DNS addresses (208.67.222.222 and 208.67.220.220 for those keeping score at home), applied my Network changes and the rest was history.

I know this is a long story but I wanted to put this out here for two reasons…

1.) I wanted to make sure that I put this somewhere so if I ever have to do it again, I’ll remember how to set things up.

2.) Just to prove how great the Mac OS is. I don’t think there’d be anyway to do this on Windows… If there is, I’d love to know. :)

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This entry was posted on Sunday, May 18th, 2008 at 7:29 pm and is filed under apple, nerd. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

3 Responses to “How Mac OS X’s “Internet Sharing” Saved My Vacation”

  1. ocomik Says:

    In windows you just turn on ICS (Internet Connection Sharing) on the host and then just route right through that box.

  2. mike Says:

    I don’t believe you. :)

  3. Owen Says:

    Thanks for the writeup, for some reason I had sharing working perfectly and it just up and stopped… I proceeded to mess with settings for ~30 minutes before finding your page and finally resetting my DNS servers to fix the issue. It works for now, so this article was the perfect length in my opinion.