Cant ping the same ip with multiple computers

This is a wierd one for me.

If I start a ping to 8.8.8.8 -t from my desktop it pings through fine for as long as I let it run. While the ping is running on the dektop i tried starting a ping on my laptop - the ping on the laptop will succeed the first time but fail continuously after that (even though the desktop can still ping). If I stop the ping on both devices, wait a few mins and start the ping on my laptop first it works, if after starting it on my laptop I start it on my desktop the laptops pings work but the desktops will succeed the first time and not after. Any suggestions? 

thanks in advance