I recently switched from openstack (due to complexity) to xenserver at work, I ran into an issue that I can't solve, I can ping the server all the time but the vms part of the time.
here is a traceroute output
traceroute to vm1 (192.168.0.74), 30 hops max, 60 byte packets
1 192.168.0.74 (192.168.0.74) 0.228 ms 0.217 ms 0.205 ms
2 192.168.0.74 (192.168.0.74) 2996.463 ms !H 2996.465 ms !H 2996.455 ms !H
administrator@staging:~$ traceroute vm1
traceroute to vm1 (192.168.0.74), 30 hops max, 60 byte packets
1 192.168.0.74 (192.168.0.74) 0.946 ms 0.927 ms 0.920 ms
administrator@staging:~$ traceroute vm1
traceroute to vm1 (192.168.0.74), 30 hops max, 60 byte packets
1 192.168.0.74 (192.168.0.74) 0.726 ms 0.712 ms 0.669 ms
administrator@staging:~$ traceroute vm1
traceroute to vm1 (192.168.0.74), 30 hops max, 60 byte packets
1 192.168.0.74 (192.168.0.74) 0.547 ms * *
The ip addresses are managed my an external router and all the machines are on the same subnet. The connected nics are bonded and the vms are setup for direct access(no vlans) attached directly to the bonded nics. Its stock standard xenserver 6.2 with almost no tweaking of the network settings.
thanks for your help