A few weeks ago (I know this dates back to November 5, 2014), I ran into an issue with the Netscaler VPX appliance where upon deployment of the appliance on vSphere 5.5, Netscaler would lose network connectivity. Essentially what would happen is that when I would boot the appliance, after it initializes all of it’s components and the network stack would come online, it would, after a few seconds stop responding to pings and essentially render useless.
As per Citrix, the main issue is:
NetScaler VPX network connectivity issue on VMware ESXi 5.1.0 build 2191751 and VMware ESXi 5.5 build 2143827 is caused by “tx_ring_length” mismatch, which causes TX stalls.
It is also important to note that when you upgrade your vSphere environment from 5.1 -> 5.5, you will most likely run into the same problem. This can also occur on various different build numbers, I can attest to that even though Citrix only states one build for each version (5.1 | 5.5).
The fix is outlined in the article mentioned above, however the fix that I’ve found seems to work as well and no need to create any new files.
In Shell, edit the loader.conf file (vi /flash/boot/defaults/loader.conf) with the following paramater (hw.em.txd=512)