I have several VMs on a hyper-V, one of them is SQL2k8. I had 1 network card, used for an external virual network which was shared between the 4 VMs.

To improve my network, I added a 2nd NIC, created a 2nd external virtual network and gave it a static IP.

So 1st NIC IP is 192.0.0.13, the 2nd is 192.168.0.12

In the sql VM setting I changed the network to use this 2nd virtual network. It gets the right configuration but when I try to connect I get very strange behaviors. I tried some pings, getting a lot of "Request time out" or 1 a reply with several Request time out like thgis :

Reply from 192.168.0.27 : Bytes=32 time=2141ms TTL=128

Reply from 192.168.0.27 : Bytes=32 time=2ms TTL=128