Avatar of d-smith
d-smith asked on

Connecting to existing (not disconnected) ICA session from different client

We recently went from plain old Terminal Services to Citrix PS 4.5. We only publish a desktop not individual apps.

When using RDP it's possible to establish a session on one client then go to another client and log in again. When users are limited to one session at a time, and they reconnect to the same server, the new login takes over the existing live session and the old client pops up a message saying so.

I'd like to do that in a load balanced Citrix/ICA environment. There's no problem connecting to disconnected sessions but when a user tries to connect to a live session they get the error "You already have an instance of this application open and are not allowed to run more than one instance..."

Any ideas? Am I missing something?
Microsoft Server OSCitrix

Avatar of undefined
Last Comment

8/22/2022 - Mon

I'm not that good with Citrix, we do use it for our apps but I just support it, not manage it, as far as I know it uses the PC/User name for authetification, so you might not be able to, unless when you run the XenApp you dont select "use machine name as client"  that's just a guess, there a high % that I'm wrong.

I believe there was a hotfix for this issue but I'm pretty sure it only applies to re-connecting to a disconnected session. It may very well fix the problem. Try installing the Citrix Hotfix rollup pack 2 for PS4.5 (cant remember the exact hotfix for it)

I'll give rollup 2 a try. I won't be able to install it until the weekend.

Please standby...
Experts Exchange is like having an extremely knowledgeable team sitting and waiting for your call. Couldn't do my job half as well as I do without it!
James Murphy

Are your users logging in via the Web Interface?

This is a feature called "Workspace Control" and can be found in the Management Console under "other tasks".  You can specify to reconnect users to disconnected sessions only, or All sessions

We're using PNAgent exclusively so Web Interface does come into play. I just checked and workspace control is set to allow automatic reconnection to all sessions not just disconnected.

actually PNAgent should work as well since you have to create a site for the PNAgent to authenticate to.  What version of the PNAgent are you using?

If you change it to allow them 2 instances of an application... does it connect to the Active Session or create a new session?
Get an unlimited membership to EE for less than $4 a week.
Unlimited question asking, solutions, articles and more.

PNAgent is 9.2,  10.0 and 10.100 didn't work well in our environment, 10.200 is in testing

Web Interface is 4.6

If "Allow only one instance of application for each user" is turned off a new session is created on each logon UNLESS the user is lucky enough to be connected to a server that's already running one of their sessions, then it works as desired. We have an 8 server farm so we can't depend on luck.

been awhile since I've used PNAgent but isn't there an option on the tray icon to "Reconect Sessions"? Is that what you are using, or are you just launching the app again?

a couple things I've found that you should also check:

From 4.5 admin guide
To use Workspace control you must enable the "Web Interface should override the ICA client name" setting in the Manage session preferences task. This is the default setting.

To enable Workspace Control on a PNAgent Site:
In the AMC (or ASC) it's under the Config.XML Node>Session Options>Workspace Control.
All of life is about relationships, and EE has made a viirtual community a real community. It lifts everyone's boat
William Peck

If UserA starts a session and
"Allow only one instance of application for each user" is off for the application and
Workspace Control is configured as mgcIT recommends and
PNAgent has authenticated to the farm as UserA then
the Reconnect option in PNAgent works as it should. It reconnects to any sessions, disconnected or not, that UserA has running in the farm.

However, if UserB has already authenticated in PNAgent, or a Wyse terminal is the new client, then UserA cannot reconnect to any sessions unless they get lucky and hit a server that's running one of those sessions.

I want to reconnect by launching the app again from a different client.

Because we use pass-through authentication in PNAgent UserA will almost never be authenticated on a new client, somebody else is almost always there first. But UserA wants to sit down and use the session they started somewhere else by launching the app again.

As I think through the process that PNAgent is probably using to reconnect a session I'm coming to the conclusion that it's just not possible to reliably reconnect to a session in a load balanced environment just by re-launching the app. A Citrix client has to pre-authenticate the user first. Am I right?

Log in or sign up to see answer
Become an EE member today7-DAY FREE TRIAL
Members can start a 7-Day Free trial then enjoy unlimited access to the platform
Sign up - Free for 7 days
Learn why we charge membership fees
We get it - no one likes a content blocker. Take one extra minute and find out why we block content.
See how we're fighting big data
Not exactly the question you had in mind?
Sign up for an EE membership and get your own personalized solution. With an EE membership, you can ask unlimited troubleshooting, research, or opinion questions.
ask a question