Troubleshoot VMware View Security Server PCoIP port problems

Recently I had to troubleshoot a VMware View Client connection problem.  In a new VMware View environment the customer has installed a VMware Horizon View Security Server for the external connections.  When a external View Client tried to connect through the Security Server using the PCoIP protocol to the View desktop the following appeared:

The connection to the remote computer ended

When the users connects to the View Desktop using the LAN (without the Security Server) everything worked fine. I suspected that a PCoIP port (4172 TCP and UDP) is blocked between the Security Server and desktop pool or vice versa. 

To troubleshoot this problem I used the tool “Netcat”. With Netcat TCP and UDP ports can be checked (Telnet can only check TCP ports). So I used Netcat  to check the TCP and UDP ports between the Security server and View Desktop (1) and the View Desktop to the Security Server(2).



Here is an example how to use Netcat:

On the View desktop  run Netcat  to listen to UDP port 4172:

nc –l –u –p 4172

On the security server run Netcat to connect to the View Desktop on UDP port 4172:

nc –u ipaddress 4172

You can type some text and press enter. The text typed in the screen must be displayed on both sides, If not the port is blocked.


So I discovered that the 4172 UDP protocol from the View desktop pool to the Security server was blocked by a firewall. After opening this port in the firewalls the problem was solved.

More information:  Netcat for Windows can be downloaded here.

VMware View 4 released


The long awaited VMware View with the PCoIP protocol has landed and is available for download.

VMware View 4.0 includes the following new features:

  • VMware View with PCoIP – PCoIP provides an optimized desktop experience for the delivery of the entire desktop environment including applications, images, audio, and video content for a wide range of users on the LAN or across the WAN. PCoIP can compensate for an increase in latency or a reduction in bandwidth, to ensure that end users can remain productive regardless of network conditions.
  • PCoIP includes VMware View Display with support for up to four monitors and the ability to deliver the optimal resolution and pivot orientation to each monitor independently.
  • VMware vSphere Support – VMware vSphere 4 support enables improved virtual machine scalability, performance, and management, with continued support for VMware Infrastructure 3.x.
  • Enhanced single sign-on – The Log in as current user feature is integrated with Active Directory and smart cards to help simplify the process of logging in to a VMware View desktop.
  • Restricted entitlements – Administrators can control user access to virtual desktops based on the View Connection Server being used for authentication.
  • Smart card policies – Administrators can set group policies to force desktop disconnection and require reconnection when users remove smart cards.
  • Domain filtering – You can use vdmadmin.exe to control the accessibility of domains and traverse trust relationships more quickly.
  • You can cleanly delete View desktops using scripts.
  • You can log in to View desktops using user principal names (UPN).
  • You can explicitly configure IP addresses to override those supplied by the View Agent when accessing a desktop.
  • Mixed Active Directory and Kerberos authentication is supported.

The VMware View 4  release notes can be find here, and the downloads are here. Next week i try to test VMware View 4 and blog my experiences.


VMware VIEW 4 useful information


After attending the VMware View 4 Talkshoe podcast the following information about the announced VMware  View 4 was discussed:

VM’s per core:

VM’s per core, In VMware View 3 the number was 6-9 VM’s per core, now in View 4 with for example the Intel Nehalem processors you can get to 12-16 VM’s per core. This number heavily depends for example on the application load inside the VM’s.

The PCoIP protocol does NOT support:

– Security Server;

– Smart Cards integration;

– Thinprint support.


– The PCoIP protocol is not different in scalability than RDP;

– For the RDP protocol version 6 is used in VMware VIEW;

– Offline desktop support is still experimental;

– There’s no RTO Software Virtual Profiles in this release of VMware VIEW 4;

– Windows  7 is still experimental, official support will be around the begin of 2010; 

– The Connection server must be installed on Windows 2003, support for Windows 2008 will be around the begin of 2010;

– Advise for virus scanning software is use VMware aware virus scanners (VMsafe), for example Trend Micro and McAfee have beta’s that use the VMsafe technology.


logo  PCoIP-150x60