Wednesday 02 June 2010

Who's the geek?

When Corwin got his XBox we needed to hook it up to the house wireless network. The XBox does not come with built in wireless so Mom decided that since we had another system in the media table that needed to be connected we should get a wireless bridge instead of the XBox wireless connector. It seemed like a good idea at the time but it turns out that if you use a Linksys wireless router and a Linksys wireless bridge, it doesn’t work.

Mom spent quite a bit of time tracking this issue down. She netsearched and discovered that many other people had this problem. One solution was buying from a Linksys competitor, which didn’t seem like a good corporate strategy to me. But Mom (haha!) had disposed of the packing material so she couldn’t send the bridge back. Instead she kept researching and finally started debugging the network packets to find out what exactly the problem was. She eventually tracked it down1 but there was no actual fix. She had to change the bridge back to routed mode (which makes certain other things annoying) but she got it to work. Yay Mom!

P.S. Corwin helped by asking Mom every 5 minutes or so while she was watching the packet sniffer output “can I play XBox now?”.

1 The bridge was messing up the IP checksum when the IP packet size was less than the Ethernet minimum packet size. I suspect it was using uninitialized memory in that case but Mom was dubious.

Posted by Dad about Parents at 21:08 | Ping URL

A couple technical corrections.

It was messing up the TCP checksum for small packets (like the SYN exchange for netflix). One might ask why the wireless bridge is rewriting TCP checksums at all.

I had to change the Wireless access point from switch to routed mode. The wireless bridge was unchanged. Since the error was on the bridge, I’m a bit confused about how changes on the access point affected anything. Presumably the packets the generate are slightly difference, but according to the sniffer they are the same (except the TCP checksum is ok now).

But the important thing is that it works now!

Posted by: Mom on 05 June 2010 at 08:02
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