Hi,

My scenario is...
Class B sub-net - 172.20.x.x /16
Multiple Virtual servers running on Microsoft HyperV 2012R2 host.
All Servers are backed up at night to NAS located in different building on a different switch - 172.20.99.247

Problem: All virtual servers are unresponsive during the backup window leading to Failover Cluster problems.

The 2 attached screen shots are the ping plots between 2 servers during the backup window.
Fig 1. during backup
Fig 2. backup disabled and NAS disconnected.

I am pretty sure it is a bandwidth issue, sending all that data across a 1Gbps Fibre link but I am struggling to interpret fig 1. - Why do other servers and switch appear as hops when packet loss occurs, especially when the 2 servers I am pinging are connected to the same switch ??

Thanks,
Graham