Cannot find this particular issue in any other thread...

I have two particular rigs running Xubuntu 13.10 - different GPUs in each.

Both rigs have identical cgminer 3.7.2 compiled and apart from one XFX R9 270 being a bit fussy with settings, all ok.

My issue is that on one rig, I can reliably run an SSH session via Putty and do:


then CTL+A d to detach, exit out of Putty - then hours later (when I get home from work) open a Putty session and do:


And I'm in there seeing my cgminer screen.

However, on the other rig - (after doing exactly as above) - when I try and Putty(SSH) in later it just times out. Can't ping the rig and 'no route to host' reported. Wierdly, I can ping the rig if I log into the firewall/router at home and ping its IP from the routers (Netgear) built in diagnostics screen... but not from box on the LAN

Only way to get back up regain SSH access is to hard reboot the rig. INTERESTINGLY - The rig carries on mining happily in isolation and is visible on the pool/s! Therefore, its still connected on the LAN, is still sending/receiving packets to pool but is deaf to ping and any other attempts to speak with it or control it...

I should add that the rig in question uses a USB Pi Hut Ralink WiFi dongle as link whereas the other rig (which is at work) is hard wired on LAN there...

Any thoughts good people?