Citrix Systems 5.6 manual Networking Troubleshooting, Diagnosing network corruption

1.Use XenCenter or the vm-shutdowncommand to shut down all VMs in the pool to force existing VIFs to be unplugged from their networks.

xe vm-shutdown uuid=<vm_uuid>

2.Use the host-management-disablecommand to disable the management interface:

xe host-management-disable

3.Use the pif-forgetcommand to remove the two incorrect PIF records:

xe pif-forget uuid=1ef8209d-5db5-cf69-3fe6-0e8d24f8f518 xe pif-forget uuid=829fd476-2bbb-67bb-139f-d607c09e9110

4.Use the pif-introducecommand to re-introduce the devices with the desired naming:

xe pif-introduce device=eth0 host-uuid=<host_uuid>mac=00:19:bb:2d:7e:7a xe pif-introduce device=eth1 host-uuid=<host_uuid>mac=00:19:bb:2d:7e:8a

5.Use the pif-listcommand again to verify the new configuration:

xe pif-list params=uuid,device,MAC

6.Use the pif-reconfigure-ipcommand to reset the management interface IP addressing configuration. See Appendix A, Command line interface for details on the parameters of the pif-reconfigure-ipcommand.

xe pif-reconfigure-ip uuid=<728d9e7f-62ed-a477-2c71-3974d75972eb>mode=dhcp

7.Use the host-management-reconfigurecommand to set the management interface to the desired PIF and re-enable external management connectivity to the host:

xe host-management-reconfigure pif-uuid=<728d9e7f-62ed-a477-2c71-3974d75972eb>

Networking Troubleshooting

If you are having problems with configuring networking, first ensure that you have not directly modified any of the control domain ifcfg-*files directly. These files are directly managed by the control domain host agent, and changes will be overwritten.

Diagnosing network corruption

Some network card models require firmware upgrades from the vendor to work reliably under load, or when certain optimizations are turned on. If you are seeing corrupted traffic to VMs, then you should first try to obtain the latest recommended firmware from your vendor and apply a BIOS update.

If the problem still persists, then you can use the CLI to disable receive / transmit offload optimizations on the physical interface.

Warning:

Disabling receive / transmit offload optimizations can result in a performance loss and / or increased CPU usage.

First, determine the UUID of the physical interface. You can filter on the device field as follows:

xe pif-list device=eth0

Next, set the following parameter on the PIF to disable TX offload:

xe pif-param-set uuid=<pif_uuid> other-config:ethtool-tx=off

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