AirPlay on Apple TV works for iOS devices but not for Macs
First thing I'd check is whether the firewall is enabled on your Macbook and blocking incoming packets. If the firewall is on, try turning it off temporarily for a few minutes to see if the AirPlay icon appears in the menubar.

Next thing to check is whether the devices are on the same subnet. You can find the IP address and subnet mask of your Apple TV in Settings -&gt; General -&gt; Network. And the IP address and subnet mask of your Macbook in System Preferences -&gt; Network -&gt; Wi-Fi -&gt; Advanced... -&gt; TCP/IP. Ideally what you should expect to see is the same subnet mask on both devices (likely something like 255.255.255.0) and IP addresses that are similar except for the number after the last dot (something like 192.168.0.125 and 192.168.0.138).

Those are the two things I'd check first. Check those and let us know how you get on.

Apple have a guide to trouble-shooting AirPlay problems for Macs. There are a few other things that might help too: About AirPlay Mirroring in OS X