After applying patches to an ESXi 5.1/5.5/6.0 host, Citrix NetScaler virtual machine with e1000 vNIC loses network connectivity

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

After patching your ESXi host to version 5.5 Update 2 (build 2143827), 5.1 Patch 6 (build 2191751), 6.0 or a later build, you experience these symptoms:

• Some Citrix NetScaler virtual machine appliance running the guest Operating System with e1000 vNIC driver loses network connectivity
• Cannot access the console after applying the patches

Environment

VMware vSphere ESXi 5.1
VMware vSphere ESXi 6.0
VMware vSphere ESXi 5.5

Cause

This issue occurs when the NetScaler virtual machine driver resets TDT to 0 after 511 while the TX ring size is shown as 1024.

Resolution

This is a known issue affecting Citrix NetScaler virtual machine appliances running on hosts running these builds of ESXi or later build: 5.5 Update 2 (build 2143827), ESXi 5.1 Patch 6 (build 2191751), or 6.0.

This is not a VMware issue. To resolve this issue, upgrade the NetScaler appliance.

For more information, contact Citrix Support and see the Citrix Knowledge Base article NetScaler VPX Loses Network Connectivity on VMware ESXi 5.1.0 2191751 and VMware ESXi 5.5 Build 2143827.

Note: The preceding link was correct as of February 16, 2015. If you find the link is broken, provide a feedback and a VMware employee will update the link.

To work around this issue when you cannot upgrade, use one of these options:

• Install NetScaler VPX appliance on a previously known good VMware version and build.
• Add the line hw.em.txd=512 in the loader.conf.local file.
  
  To add the line hw.em.txd=512 in the loader.conf.local file:
  
  
  1. Log in to the Citrix NetScaler virtual machine appliance as root.
  2. Locate the loader.conf.local file on the NetScaler virtual machine appliance by running this command:
     
     find / -name loader.conf.local
     
     Note: The loader.conf.local file may not exist. If so, create this file under directory /flash/boot.
     
     
  3. Add this line in the loader.conf.local file.
     
     hw.em.txd=512
     
     
  4. Save the changes.
  5. Restart the NetScaler virtual machine appliance.

Additional Information

ESXi 5.1 および 5.5 ホストにパッチを適用すると、e1000 の vNIC を搭載した Citrix 製 NetScaler 仮想アプライアンスのネットワーク接続が切断される
对 ESXi 5.1/5.5 主机应用修补程序后，使用 e1000 vNIC 的 Citrix NetScaler 虚拟机失去网络连接