Technology Hints

My family spent this Christmas vacation in Las Vegas. This was the first time we’ve done this. We usually spend our Christmas vacation at home. However, our Navy daughter is going to be deployed to Afghanistan next month and we won’t see her for over a year and she said she’d like to spend this Christmas time in Las Vegas. Given that she wasn’t going to be able to have any fun for over a year, we went with her request.

One thing I really don’t like about Las Vegas is that none of the strip hotels (that I’m aware of) offer free Internet access. You have to pay through the nose for it. This was going to be a big problem for us, since there were four of us and everyone wanted to use the Internet while we were there. The hotel we ended up staying at was charging 10 dollars a day for Internet. So, if all of us wanted to connect, it would be forty dollars a day for four days, or 160 dollars! There had to be a better way.

A solution that I’ve used before is to put a NAT device in front of my computer. I’ve done this in the past to solve the VPN problem related to the hotel network having the same network ID as my office network. As you know, the source and destination networks IDs need to be different when establishing a remote access client VPN connection. This wasn’t my problem this time, since I’ve implemented ORB and Foldershare for remote file access.

My problem this time is was that I didn’t have a cable connection at this hotel. They only offered a wireless connection. The problem I needed to solve was to get myself, my wife, and our two kids on the Internet using that single wireless connection.

I solved the problem by reconfiguring my wireless NAT device (I never call them “routers” since they don’t actually route connections, just NAT) into a wireless bridge. This configuration change was easy using the Web based interface on the Belkin wireless NAT device I picked up the day before leaving town (my “travel” NAT device died in an accident).

After changing the NAT device into a wireless bridge, I changed the IP address of the Ethernet port on my laptop to 192.168.2.1/24 and instructed everyone to assigned themselves an IP address on that network ID and make my computer their default gateway for their wireless NICs.

I then enabled Internet Connection Sharing (ICS) on my wireless NIC and then connected to the hotel’s wireless network.

Next, I configured the NAT device with an SSID and to use WPA2 with a pre-shared key. They were able to connect to the WLAN I configured and once I got through with paying for the Internet connection, they were able to connect to the Internet.

You probably think that this is configuration was self evident, but it wasn’t immediately obvious to me how I was going to solve the problem of only having a wireless connection to the hotel network. The reason for this is that I’ve been used to using a wired connection to the hotel and plugging the hotel connection into the public interface of the NAT device and plugging my laptop into the private connection, so that I would be assured that my network ID was different from the network ID used in my office.

What I didn’t think about at first was that my laptop, which has a wireless NIC and an Ethernet interface is that my laptop was a multihomed device and thus I could use ICS to share the hotel wireless connection.

We did end up having to create a remote access VPN connection to our office ISA Firewall, which meant that during the duration of the VPN connections, everyone needed to configure their browsers to be Web proxy clients of the ISA Firewall, which worked fine. I’ll discuss the details in a future article on how you can create a “poor man’s” site to site VPN using ICS in a branch office scenario.

That’s it for now. If you have your own tricks to share hotel wireless connections, let me know!

Thanks!

Tom

Thomas W Shinder, M.D.