Sounds like a commercial from a drug company “Network Problems Can Cause Adverse Side Effects…sleeplessness, chest pain…”, but, I digress.

Let me set the stage of my testbed configuration: On Windows XP SP2, my default connection to the Internet is via wireless express card modem using EV-DO via Verizon Wireless. Let’s call this connection A. I also have a traditional wireless network connection (802.11g) that is always enabled. Let’s call this connection B. Connection A is always connected during normal business hours. Connection B is not and is often searching for a wireless network to connect to when nothing is in range.

Yesterday, connection B was continuously trying to connect to a wireless network not under my control, meaning that the connection was never established and notification messages continually popped up to complain of this fact. Over time, I’ve learned to ignore these messages and go on doing my daily work without much thought of the possible implications.

Then, things started to get odd. I was running our application, WebWatchBot, to perform some simple tests of various websites and servers, when I started to get messages from the application that database connectivity was lost, which is a message that pops up to inform the user that the connection is forcibly dropped by SQL Server. After a few moments, the connection to the database was re-established and the message went away. Since I was actually working with SQL Server, I thought it was an anomoly, so I continued on. Then, it happened again. And again. Then, I noticed that the “database connectivity lost” message started to coincide with the wireless connection’s (connection B) inability to connect with a wireless network.

Why would this be happening? The database and application are on the same exact computer. The connection to the database is via ODBC drivers over tcp/ip, but why would connection B affect this?