VMware Horizon View: disconnect – reconnect every 30 odd seconds in RDP session

One of our customers complained of a disconnect – reconnect every 30 seconds of sessions with virtualized desktops (Horizon View 5.3.1). We tried it ourselves and got the same results. After about 10 disconnect – reconnects we got the message in the Blast portal “unable to reconnect”. With a security specialist and a network specialist we started to troubleshoot, aiming to isolate the problem. We have a setup with a virtual wire for the VDI desktops and another vWire for the servers they have access to, we use the Blast portal to publish the virtual Windows 7 desktops for the customer on a private network. Access is fenced of with a firewall on the outside perimeter, a TMG to publish the URL of the Blast portal, and for the translation of the Blast portal port to 443 we use a Sophos appliance. Not really a very simple setup.

Anyway as the Blast portal didn’t suffer from the time outs and disconnects, we could rule out the TMG pretty fast. Soem other simple test showed that the problem couldn’t be in the Sophos appliance either. Then we continued our tests with rdp sessions between the virtual desktops. There we found no problems. Then RDPto machines on different virtual wires… and we got freezing sessions. So we could rule out Horizon View Broker and Agent as the cause of all evil.

We set off to examine the vCNS Edges… and there we found a problem. The autogenerated default internal rules were missing from the responsible Egde, so we had no HA rules present on the Edge, causing connection problems.


The solution was to enable auto rule generation…



And voilà, problem solved!

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About etqui

My name is Eelco de Boer and I work for DellEMC as a Technical Account Manager. I am interested in design (both high level and technical), product/solution management and helping customers solve their pains. I like to take a broader look and approach and prefer to look at a problem from several angles. My experience focuses mainly on solutions based on VMware technologies and software. I am a VMware Certified Professional, VMware Certified Advanced Professional Data Center Design, vExpert 2014, 2015 and 2016. This blog represents my own opinion and views.

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