Windows Live Messenger - Malformed Packets J. Jerzak 02.07.2007 16:12:03 I have traced a recurring network outage at work to Windows Live Messenger on my machine. A few days ago people started reporting no internet connectivity. Our current network configuration has about 20 users with access through a TimeWarner high speed connection. Regardless of the amount of network traffic, users were reporting no connectivity. I could restore service by power cycling the TimeWarner connection. I had Time Warner out to test and replace the modem. ***Lot's of other troublehooting that I won't get into here as it was irrelivant... ....then I ran a packet sniffer on the connection between the switch and the firewall which would show all internet traffic. One IP address reporting malformed packets around the time of the connection loss. I checked the DHCP leases... it was the IP address of my machine. I verified that this issue only occurred when my machine was on the network. I installed and ran a packet sniffer on my machine logged in as admin... the internet connection stayed healthy. I reviewed what would be different between admin account and my user account. Might be messenger. I logged into Windows Live Messenger. I watched the packet sniffer collect data and realized the IP address that Windows Messenger was communicating with was familiar from the previous analysis which showed malformed packets. I watched and waited. I started seeing malformed packets appear on in the Windows Live Messenger communication packets. Within a few seconds, the continuous ping to google.com from another machine began failing indefinately. I power cycled the modem again and closed Windows Live Messenger. All is well. However I would like to be able to use messenger. Any insight would be greatly aprreciated. Thanks!