Problem with Internet on guest machine Hyper-V

Sorry my bad English. I have a server running windows server 2012 r2 datacenter and setup Hyper-v. I already create a vNic bridge to physical network. I have 3 public IP 42.112.xx.168,169,170 42.112.xx.168 255.255.255.0 42.112.xx.1 set to physical network, Internet working ok

I create a VM on hyper-v and select VNIC as a network adapter, and set the IP 42.112.xx.169 255.255.255.0 42.112.xx.1 but got no internet, I tried to reset the VM got same error. BUT after I reset the host machine, the VM got internet.

So I try to create more VM and set the last IP 170 to it, and got same error. Only have internet after reset host machine. And sometime I lost internet again when reset the host machine again.

Pls help me !