why GCM is not giving push notification in android device?

Question

I am new to android and doing a demo app for gcm push notification.

I have developed all this code and GCM push notification is coming on devices in my environment, but

Answer 1

Try to ping google.com from your server. If it is not success try to investigate your server configuration.

E.g. Check you /etc/resolv.conf and see if you have:

nameserver 8.8.8.8
nameserver 8.8.4.4

Answer 2

At last I found the reason.My company firewall was blocking all messages from GCM. So I just removed firewall and able to receive messages from GCM . Go through this link to know more about firewall issues

Hope it will help somebody in future.