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
