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.
Author: Dale Scriven