What an interesting problem. I don't yet have any answers, but I'm intrigued. And your knowing enough to break out ethereal makes me believe that it's not just a user error. Could you please tell up a couple more things? 1) What make and model of a router is this (even firmware revision may help pin this down). I would also look to see if I could find any similar reports of things like this with this router, and see if there are any firmware revisions available. 2) Please post the output of ifconfig. Please dont obscure any IP addresses or related data, any IP addresses shown should be private NAT addresses and there is no reason to obscure them. I may not get back to you for a little while, but I will be thinking about this one.