No AV on the server. Viewer has been used on machines with Kaspersky AV and also a machine with just Windows Defender (i.e. nothing), same results. Host machines both with KAV and without exhibit the problem as described.
I think that pretty much rules out AV.
Aside from the firewall appliance in front of the RU server, no software firewalls are used.
I'll see if I can get some logs from the ru-server and viewer.
Using viewer 22.214.171.124, host 126.96.36.199 and ru-server 188.8.131.52
ru-server is hosted in a DC, viewer and host are on different business-grade connections
My problem is as follows:
Host shows as online
Attempt to connect (any action, doesn't matter)
Instantly get 'Unable to connect. Attempts left: ' dialog. Host now shows as offline
When dialog times out after 5 attempts, host will show as online again after a short interval
Here is a short screen-cap demonstrating the issue:
A temporary solution appears to be to restart the ru-server, but this doesn't always last very long. The issue varies in how frequently it presents.
I suspect something happens with the firewall in front of the ru-server that the ru-server/hosts don't recover from or the lack of IPv6 on the ru-server (most of the hosts are dual-stack with IPv6 connectivity but the ru-server is not currently configured with an IPv6 address)
This is quite problematic for us as not all operators have access to restart the ru-server (not to mention it is very frustrating when it does it multiple times in longer support sessions).
I really like the product but it doesn't seem to work in some scenarios.
Host agent shows as 'Ready for connection' (every ~5mins it briefly flicks to 'Connection not available' then 'Connecting...') Viewer sporadically shows host as 'Online' but as soon as we try and connect it goes offline. [censored] is working fine, so I'm not sure what the issue is.
Any help is greatly appreciated as we would love to get RU working on these sites.