Can't backup VMs on same host as proxy

[PhilLarby]

Our Veeam setup has always had a physical veeam server which runs as the proxy and is connected over Ethernet. I'm now trying to improve performance by creating a proxy on a VM and changing from network transport to hotadd.

This all seems good, except that I can't back up any VMs that exist on the same host as the new proxy's VM. These are ESXi 5.5 hosts. The error in statistics is that the file does not exist or is locked. It seems from the proxy logs that the proxy never manages to establish an NFC connection.

If I move the proxy VM to a different host, the same problem affects all VMs on the new host. Once moved, the proxy can back up all the VMs on the original host that were previsouly failing.

If I use the original physical server for the proxy, all VMs back up OK regardless of host - all be it very slowly!

Have you got any pointers where I should be looking, or what could be set up wrong as I'm a bit lost right now! I have a support case id: 01704147

[haslund]

I am wondering if this could either be something related to DNS or time. Is the virtual proxy VM able to resolve DNS for all ESXi hosts?