[ovirt-users] Virt-viewer not working over VPN

Hi, I asked this on the virt-viewer list, but it appears to be dead, so my apologies if this isn't the right place for this question. When I access my vm's locally using virt-viewer on windows clients, everything works fine, spice or vnc. When I access the same vm's remotely over a site-to-site VPN (setup between the two firewalls), it fails with an error: unable to connect to libvirt with uri: [none]. Similarly I cannot connect in a browser-based vnc session (cannot connect to host). I can resolve the DNS of the server from my remote client (domain override in the firewall pointing to the DNS server locally) and everything else I do seems completely unaware of the vpn link (SSH, RDP, etc). For example connecting to https://ovirt-enginr.mydomain.com works as expected. The only function not working remotely is virt-viewer. Any clues would be appreciated!