Cannot ping/communicate with Android devices on the same network

Question

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.

Cereal

How are you pinging? (Post code) – Yepez

ping 192.168.1.103 also tried ping android-81ecbc3024ac2dd2 which is the host name given to it by my home router – Cereal

Via command line, via code? – Yepez

Answer 1

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

Bolster

Tried that, wifi is set to never sleep. – Cereal

Additionally there is no firewall on any of the machines/devices. I am able to ping other devices on the same network – Cereal

Have you got connection to the internet on the device? Can you reach any websites? – Bolster

Answer 2

I think you can install the networking message monitor on your laptop like "wireshark". And then make sure the ping messages have been received in laptop.

If the laptop has been received the ping messages, and then do it reverse ping smart phone by laptop.

If you do these things you can confirm which machine the problem is on.

Looking forward to your reply！

Thanks.

Crash