I have a very strange network issue which isn't making a lot of sense.
Basically there are two sites, site A and site B connected by a VPN - 30mbps connection at each site.
Site B has a VMware infrastructure with iSCSI connectivity.
Site A has several physical servers and a VMware infrastructure with SAS connectivity.
I can ping the servers at each site, RDP to servers, login to the vSphere clients, access OWA on the Exchange server in the alternate site.
However, I cannot connect to the vCentre server on site B through vSphere, which in turn means the Veeam replication jobs cannot connect either.
Also the Exchange 2010 servers stop communicating so the DAG between the sites stops communicating and causes all sorts of issues.
I have repaired several times by either replacing the virtual network cards on the VM's or resetting the Winsock.
It will work for a while and then stop, its very sensitive to any changes and it just stops working.
I have taken a Wireshark of the traffic and I can see the connection errors and is reset
I can see the same when I try to resynch the Exchange DAG...
The VPN allows all services both ways and nothing is logging on the firewalls to say that traffic is being blocked....