Error observed when configuring VDS port mirroring sesion type Remote Port Mirroring: "Traffic cannot be disallowed in the Remote Mirroring Source session".

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

• Error similar to the below is observed when attempting to configure VDS port mirroring session type 'Remote Mirroring Source':
  A specified parameter was not correct: spec.vspanConfigSpec[].vspan Session.destinationPort.uplinkPortName[] Traffic cannot be disallowed in the Remote Mirroring Source session because the uplink port <Uplink Port Name> is in use by the team policy defined at DVPortgroup <dvPort Group Name>.
• Remote Mirroring Source session type is being configured.
• Normal I/O on Destination Ports is set to 'Disallowed'.
• Source port for mirroring session is using dvPort Group <dvPort Group Name>.
• Destination uplink for mirroring session is using <Uplink Port Name>.
• The teaming and failover policy for <dvPort Group Name> includes <Uplink Port Name> as an 'Active Uplink' in its failover order.

Environment

VMware vCenter Server

VMware ESXi

Cause

If 'Normal I/O' is disallowed on a destination port, vSphere prevents any non-mirrored traffic from using that physical uplink. However, if that same uplink is defined as 'Active' in a port group's teaming policy, a conflict arises.  The port group requires the uplink for production traffic, but the mirroring session mandate is to block all standard I/O.

Resolution

This behaviour is expected.

Workaround 1
Edit the port mirroring session feature 'Normal I/O on Destination Ports' to 'Allowed'. 

Workaround 2
Edit the teaming and failover policy for <dvPort Group Name> to move <Uplink Port Name> in its 'failover order' from 'Active Uplinks' to Standby Uplink'.

Additional Information

Create a Port Mirroring Session