Cannot ping between OS X on wireless LAN
First, it seems your wireless router seems to have some firewall part preventing ICMP messages (ping is one part of this protocol suite) going over the wireless lan to prevent a ping flood. To verify this, try out these tests:


Disable any VPN software you may run (VPN software mostly includes Desktop policies preventing "unwanted" protocols to be executed and they insert special routes).
ping -c2 192.168.0.255


A usual behaviour for that command would be to get an answer from all your machines in the same network. If this doesn't work, something else is preventing that. As you wrote you disabled all the OS X firewalls, this command should be successful.

To verify this, go to step 2:


Take two MBP and connect them with one CAT6 Gigabit Ethernetcable and assign IP adresses to the LAN ports:


MBP1: en0: 172.16.42.5 netmask 255.255.255.0

MBP2: en0: 172.16.42.6 netmask 255.255.255.0

MBP3: en0: 172.16.42.7 netmask 255.255.255.0


Now try to ping MBP2 from MBP1 and vice versa and take notes:

MBP1 -&gt; MBP2: 1-&gt;2 yes / no, 2-&gt;1 yes / no

MBP1 -&gt; MBP3: 1-&gt;3 yes / no, 3-&gt;1 yes / no

MBP2 -&gt; MBP3: 2-&gt;3 yes / no, 3-&gt;2 yes / no


If all of these connections are working, then you know the router is the bad guy. Take a closer look in your router configuration and look there for terms like "broadcast storm", "ping flood" or "ICMP broadcast prevention". Switch that feature off and try it again.

Hope this helps in analysing your annoying trouble. :-)