Losing connection to Windows servers

I have been having a conenction problem over wifi on my mac for sometime, it appears as though it loses internet connection but this is because it loses conenction to the DNS server which is on a Windows server, at seemingly random times mt macbook cannot "talk" to Windows, on my network I have Cisco equipment (router and AP), and ESXi server, some Sonos equipment and a couple of camera's, I have Linux and Windows VM's, when teh connection goes I can ping ALL the equipment apart from the Windows VM's, from a windows laptop this does not happen so it is not the windows servers themselves, the only things that stop communicating is the Macbook with the Windows servers, after about 10 seconds of unresponsive pings it all springs back into life, I have tried changing MTU but this makes no difference, I am now on El Capitan but it also happened on Yosemite, any ideas?