Loss of WAN access

[prpr]

Periodically, my HDR-T2s lose internet access. This has been observed on more than one box, not all at the same time, and with boxes on different ADSL connections.
This morning one of them was in this state so I finally had a chance to do some digging with Tcpdump (it was also useful in testing for this thread http://hummy.tv/forum/threads/a-quickie.5698/).
It seems like everything that goes out on the LAN has the correct source IP address, but everything that is destined for the WAN has 0.0.0.0 as the source IP, which obviously makes it impossible for the remote end to respond, and is why you lose access.
Everything looks normal when doing "route -n" or "arp -n". The "-n" is necessary as otherwise you get a 30s delay for each entry as it tries to do a DNS lookup to 208.67.222.222 which obviously fails (as the source IP is 0.0.0.0).
Rebooting is obviously one cure. I found another by doing "ifdown eth0; sleep 5; ifup eth0" from a telnet session.
What really intrigues me is what causes it to go into this state though. Anybody got any ideas or any further tests to suggest the cause?

 

[kevindickinson]

Are you using DHCP? Could be end of lease?


Sent from here using a computing device.

 

[prpr]

Are you using DHCP? Could be end of lease?

Yes, but on sticky IP addresses from the server (in the router). "ipconfig" reports the correct address and I see no reason why it wouldn't be automatically renewed anyway seeing as both devices are always on. If the lease had expired and it hadn't been renewed, then it wouldn't have the correct IP address, would it?