Thanks Toby. From: "Toby Corkindale" <toby@dryft.net>

Here are the results of KVM and LXC based virtual machines on Ubuntu 14.04.. Both look a fair bit better than the results you're seeing.

--- LXC ping from VM host --- 10 packets transmitted, 10 received, 0% packet loss, time 9000ms rtt min/avg/max/mdev = 0.042/0.050/0.074/0.009 ms

That's in the same kernel so that should be better. Here are FreeBSD jail version 1 (shared network stack): 10 packets transmitted, 10 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 0.016/0.019/0.025/0.003 ms .. and jail version 2 (VIMAGE/VNET, own network stack) 10 packets transmitted, 10 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 0.236/0.280/0.321/0.030 ms results. Looks as there is significant overhead in the later.

--- KVM ping from VM host --- 10 packets transmitted, 10 received, 0% packet loss, time 9002ms rtt min/avg/max/mdev = 0.188/0.306/0.402/0.057 ms

Compared to Oracle VM(Xen)

...

10 packets transmitted, 10 received, 0% packet loss, time 9002ms rtt min/avg/max/mdev = 0.554/0.605/0.646/0.037 ms

It's nearly doubling the speed.. I wonder whether this is typical for KVM vs. Xen, and how VMWare ESXi is faring. I do not have a KVM or ESXi setup ready but will try. Thanks Peter