2 years ago (October 2012) I wrote in ctxdom.com about #Citrix Virtual Distributed Switch.

You can read this article on the Following link: ctxdom.com

There is a very important little point in implementing DVS. -Enable it on XenServer.

To perform this task, we logon on XenServer and run the following command inCLI.

xe-switch-network-backend openvswitch

This is very important, and that redirects all internal traffic through DVS and allows the performance of various tasks such as:
ACLs and QoS Policies; NetFlow; Traffic mirroring, Port Bonding & Per VMtraffic policy.

More info: http://support.citrix.com/article/CTX129669

If you need Disable this funtionality, you need run this command:
(dvs use can cause certain problems of congestion in some environment)

xe-switch-backend network-bridge

It is important to know the procedure to run this configuration. These are the recommendations:

1.Disable HA (before Any maintenance).
2.Migrate VMs off of host.
3.Enable bridge mode via command line: xe-switch-backend-network [bridgeoption]
4.Reboot.
5.Migrate VMs back.
6.Enable HA.

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