Note: Citrix recommends that you download the latest version of Citrix Workspace app version 1904.1 or later and Receiver for Windows to LTSR 4.9 CU6 version 4.9.6001 or later that contain critical security fixes.For more information, see the Knowledge Center article CTX251986.
Applicable Products
Symptoms or ErrorDifferent types of networks may have different MTU/MSS requirements, which may result on packets being fragmented when transmitted on those networks. This can cause issues with applications that use UDP as transport protocol due to improper handling of UDP packet fragmentation. In the case of Citrix XenApp and XenDesktop / Virtual Apps and Desktops, this affects EDT since it is a UDP-based protocol. These issues can result on performance issues in ICA sessions, on EDT connections failing and falling back to TCP, or even not being able to establish a session altogether.
Environment: XenApp and XenDesktop 7.15 or Citrix Virtual Apps and Desktops 1808+ EDT-capable Citrix Receiver / Workspace app:
SolutionCitrix Virtual Apps and Desktops 7 1912 LTSR and Workspace app for Windows 1911 introduced support for EDT MTU Discovery. If using these versions (or newer) of the VDA and Workspace app for Windows, this workaround is not required. Please review the documentation for more details.This workaround is needed if using VDA 1909 (or older), Workspace app for Windows 1910 (or older), or Workspace app for Mac, Linux, or iOS. The workaround involves lowering the EDT MTU to a value that will not cause fragmentation. This MTU value needs to be determined for each network. A tool like mturoute.exe can help determine the appropriate MTU for a network. When using Azure:
Steps Citrix Receiver 4.9.7 Download![]() 1. Define the EDT MTU and Output Buffers Length in the ICA file template in the Storefront server:
Open the default.ica file for editing (by default it is located in C:inetpubwwwrootCitrix<StoreName>App_Datadefault.ica)
Add the following options under the [Application] section: OutBufLength=1480 udtMSS=1480 (add this line if using Receiver for Windows 4.9 - 4.9 CU3, Workspace app for Linux 1808 - 1903, Workspace app 1808+ for Mac or iOS) edtMSS=1480 (add this line if using Receiver for Windows 4.9 CU4+, Workspace app for Windows 1808+, Workspace app for Linux 1906+) Notes:
If unsure whether to use 'udtMSS' or 'edtMSS', add both. The client will use the appropriate setting and ignore the one that does not apply.
edtMSS and OutBufLength should be set to the same value.
1480 was used as an example. Replace 1480 with the value that's appropriate for your network. The client and server will agree on sizes during the connection negotiation. 2. Enable Receiver/Workspace app to read the custom EDT MTU and Output Buffers Length values. NOTE: If using Receiver for Windows 4.9 CU4+, Workspace app for Windows 1808+, or Workspace app for Mac 1809+, the configuration described below is NOT required, so step 2 can be omitted.
Create UDPStackParameters registry key, which is missing by default:
HKCUSOFTWARECitrixICA ClientEngineConfigurationAdvancedModulesUDPUDPStackParameters There is a legacy issue in these Receivers for Windows where OutbufLength, when passed in an ICA file, is ignored. Even if the registry value is modified to '*', meaning accept everything from the ICA file, the ICA file setting is still ignored. For this to work, in addition to creating the 'UDPStackParameters' key as mentioned above, it is also necessary to modify the OutbufLength value in the registry and set it to the desired value determined above (1480 in the example): Citrix Receiver For Mac 12 4
HKLMSOFTWAREWow6432NodeCitrixICA ClientEngineConfigurationAdvancedModulesTCP/IPOutbufLength
HKLMSOFTWARE CitrixICA ClientEngineConfigurationAdvancedModulesTCP/IPOutbufLength
Citrix Receiver 4.5 Download
Modify the appropriate App Property to allow Receiver to read the customer parameters in the ICA file. This property is set to NO by default.
To do this, open Terminal and run: defaults write com.citrix.receiver.nomas UDPStackParameters -bool YES
Toggle the the 'Read EDT stack parameter' option, which is disabled by default:
Settings > Advanced > Adaptive Transport Settings > Read EDT stack parameter
Enable the 'EDT Stack Parameters' option, which is disabled by default:
Settings > Advanced > EDT Stack Parameters Problem Cause
MTU alteration not accounted dynamically by EDT, and IP Fragmentation not handled properly by network appliances.
Citrix Receiver For Mac 10.14Additional ResourcesComments are closed.
|
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
December 2020
Categories |