Remote site switched to MPLS WAN Link, Citrix XenApp and Web Interface no longer working

Posted on 2009-12-21
Last Modified: 2013-11-21
I have four sites all worked fine on private point-to-point T1 WAN links back to headquarters. The Citrix PS 4.5 farm is in headquarters. We recently switched one of our sites to MPLS (3x T1's MLPPP) and all site-to-site traffic works except for Citrix XenApp PNA and Web Interface connections. All other sites continue to work fine using private point-to-points WAN links. I can ping between sites and routing is working with static routes.

XenApp just shows connection in progress....
Web Interface never logs in with FQDN, but IP logs in but App result in XenApp Connectionin progress hung....

Question by:lseeman
    LVL 4

    Expert Comment

    couple of tests

    1. is PING working both ways
    2. are we able to telnet on the port required for this to work from source machine.
    LVL 1

    Author Comment

    * I can ping in all directions by IP or FQDN
    * I tried removing the HKLM registry key .../mslicensing/store/Licencexxx
    * Web-interface (WI) loads but login never processes with fqdn, but logs in via IP URL
    * Executing citrix published app via XenApp PNA or WI hang at Connection in progress...

    * I removed all in between appliances; router to router still no good
    * All other remote sites to headquarters work fine for Citrix
    * I can telnet from the affected site computer(s) on port 1494, 80, 443; all are open and listening with ICA...

    I AM STUMPED!?!?!?!?!
    LVL 1

    Author Comment

    One thing that is strange, is I cannot login to WI using computername or fqdn; but I can using IP from the remote site. Even so, neither let me get a published app to launch.....PNA or ICA client hang at Connection in progress.

    As far as the infrastructure, the only thing that changed is the following:

    1. remote site router went from using single serial private t1 to multiple serial bonded t1's over MPLS

    2. at headquarters, we have an additional router connected to same lan switch as original router interconnected the MPLS WAN link to the production network via static routes.
    LVL 1

    Author Comment

    I discovered one computer that works.  The only difference is that there is a MSTS license under hklm/microsoft/mslicensing/store. All other computer are not getting new licenses after deleting this key.

    It appears that the MSTS licensing server is not issuing device cal' this site. All 3 other sites work fine though....
    LVL 1

    Author Comment

    Turns out after much analysis and troubleshooting, I am 95% confident the problem is on the MPLS carriers side (PaeTec). The issues might be a result of PPP we're trying fram-relay encapsulation....

    Stay tuned....
    LVL 1

    Accepted Solution

    I resolved the issue by identifying an incorrect MTU and encapsulation issue on the MPLS carriers network, which was causing improper packet handling and timing. We went from PPP to FR encap on one side and removed any MTU settings on edge routers.

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