Citrix NetScaler and VMware vSphere build 2143827 issues

Citrix vmware

Its recently been reported that Citrix NetScaler VPX networking fails on hypervisors running VMware vSphere build 2143827. The symptoms include a complete failure of any networking in or out of a Citrix NetScaler appliance with multiple VPX firmware revisions affected.

There is currently no solution to the issue as of yet except running the NetScaler on a non patches vSphere host or rolling back the update by rebooting the ESXi host and hitting SHIFT-R during the booting process to revert ESXi to the previous patching level.

I will update this post as an when an official solution is released from either Citrix or VMware.


Update 1 

Ok so there is still no official fix from either VMware or Citrix but the below appears to work for about 90% of cases,


1/ Putty onto the NetScaler and then type ” shell” and enter.

2/ navigate to /flash/boot/defaults

3/ edit the loader.conf

4/ add the following to the bottom of the config file add “hw.em.txd=512”

5/ save the change and exit the config file, reboot the vpx and test.


This should resolve most cases of the problem although I have seen mentions that this does not work for some. I believe Citrix are working on a fix which hopefully will cover a decent range of major revisions as a lot of customers are still utilising 10.0,10.1.



Author: Dale Scriven

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