Cannot ping/communicate with Android devices on the same network
I have a nexus 7 running CM10.1 . For some reason i cannot reach it from my laptop on the same wifi network. I cannot ping in either direction. In the past i have been only able to ping one way.
Just tried out on my stock htc sensation and havent the same issue. Also the nexus and htc cant reach each other either.
I have had similar problems with other android devices, in the past i was developing an app and i could not establish a socket connection from the android device to my computer. Once i was able to successfully ping the laptop form my device everything worked.
This isn't persisant, in the past i fiddled around they eventually talked but there was no consistant solution at the time, i never got to the root cause.
I have obvsered this on 2 different wifi networks
Not sure what is happening here my understanding of networks isn't this deep.
Answer
My first guess (assuming you're using the right IP, no firewall conflicts etc.):
Check the WiFi Sleep Policy in the WiFi-Settings of your device. You should set it to Never and then try to ping it once more.
That's the way you'll find the option on your android device:
Settings -> Wireless & Network Setting -> Wifi Settings -> Press Menu button -> Advanced -> WiFi Sleep Policy