Ace- Are you seeing the LAN go down every XX minutes? I had an issue like this with one of my controllers and did the following until we were able to get it replaced- in Vxworks, issue the command period 840,mips_reset - this will reset the LAN port every 14 minutes(in seconds), or modify it to the "seconds" that work for you . Quick hiccup that no one will realize even happened. I used 14 minutes because our port would shut down every 15 minutes, like clockwork. This should stick until a controller reboot.