First of all this is really just a cut-and-paste from a talented co-worker, Jason Allen.

All I ran into an issue with XenDesktop 7.1 and Storefront 2.1. I was having long log on times when connecting via storefront internally (30 seconds) and it was all on the HDX connection. If I logged on via the Netscaler the logon was 10 seconds. After going through Citrix escalation we saw that the receiver/XD7 was trying to connect via 2598 and would time out and default to 1494. I had specifically disabled session reliability via policy which disables the 2598 port listener. Apparently this causes an issue with XenDesktop 7.1. I removed the session reliability policy (left it default at not configured). Rebooted the servers so 2598 listener was listening and problem was gone. So keep this in the back of your head and do not explicitly deny session reliability in XD7.1. Hope this saves you guys from some headaches!

Further research by Jason also found that the issue only appears if session reliability is disabled AND the firewall is on.  Quoting him below.

“Guys – I just tested this in my lab today, the issue only appears when session reliability is disabled AND the windows firewall is on. Even though 2598 is allowed through the windows firewall it was still causing a problem. I tested with session reliability disabled and windows firewall disabled and the connection speed was normal. I emailed this information to the Citrix Escalation engineer but thought I would share my findings.”

Hope this helps anyone.  Personally I usually leave Session Reliability on in my deployments but most people who have done this a while always leave it off.  XenDesktop 7 and 7.1 have greatly improved the feature but also the need for it is the proper determining factor. Anyone, hope this helps a few people out there and if you are a customer in Boston, know Presidio has some great engineers up that way and we’re looking out for you.