we have `Ubuntu 16.04.2 LTS` running on Hyper-V.
Connectivity to Ubuntu is unstable. Pings are stopping every 5-10 seconds for few timeouts from management station in different vlan. But if i ping from server to station or to outside server it stopps less frequently.

`cat /var/log/syslog` do not show any suspicious lines. 
It seems like a problem with OS itself, because other servers on same or different vlan are working correctly. 

This OS is freshly installed.

`top` shows cpu 0% utilization, free memory 3.7GB

How to troubleshoot further?

EDIT: i also tried installing legacy network adapter in `Hyper-V` but then checking in `etc/network/interfaces` is old `eth0` but `ifconfig -a` shows interfaces `enp0s10f0` and `lo`