Information
An interface in full-duplex mode can handle more network traffic, improving service availability and the speed of management actions such as migration and backups.
http://support.citrix.com/article/CTX117568
Solution
By default interface speed and duplex mode are automatically negotiated. Before setting these manually, ensure the switch or other device the interface is connected to can support the desired settings. Reconfiguring the management interface requires console access, because SSH connections may be lost. To reconfigure an interface run this command, substituting your desired speed and duplex mode:
xe pif-param-set uuid=<pif_uuid> other-config:ethtool-autoneg='off' other-config:ethtool-speed='<100|1000>' other-config-duplex='<half|full>'