Randomly Need to disable and re enable Networking to Work

[GreyGeek]

See No wireless connections after sleep/suspend over on Ubuntu Forums. It has a 'solution' that you might want to explore.

Thanks, Snowhog!
Here is what my /var/log/pm-suspend.log.1 file showed

Running hook /usr/lib/pm-utils/sleep.d/55NetworkManager suspend suspend:
Having NetworkManager put all interaces to sleep...Failed.
...
Running hook /usr/lib/pm-utils/sleep.d/60_wpa_supplicant suspend suspend:
Failed to connect to wpa_supplicant - wpa_ctrl_open: No such file or directory
...
Running hook /etc/pm/sleep.d/60aiccu resume suspend:
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service aiccu restart

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the stop(8) and then start(8) utilities,
e.g. stop aiccu ; start aiccu. The restart(8) utility is also available.
aiccu stop/waiting
start: Job failed to start
invoke-rc.d: initscript aiccu, action "restart" failed.
...
Running hook /usr/lib/pm-utils/sleep.d/55NetworkManager resume suspend:
Having NetworkManager wake interfaces back up...Failed.
...

Neat! Even tells you which modules or scripts failed to restart. I suspected the aiccu driver but the problem persisted after I removed it.

That brings up a problem. Restarting modules is one thing, but this method doesn't promise to restart scripts. I'll have to play around and see.

EDIT: I re-enabled the wireless device on my laptop and connected to my wireless router. My connection to eth0 remained. Then I proceeded to search the internet about this sleep problem. After a period of time my connection failed to respond and DNS was not active. Both the eth0 and wlan0 failed to work. I turned off the wireless device and restarted my eth0 device and got my connection back. So, it appears that the problem is with my wireless drivers, ath9k, not the sleep mode, since my eth0 connection has been working flawlessly for days.