Port mirroring session reporting source as failed, with error: "Field level validation errors: {mirror_sources[0].port_ids has violated the minimum valid size 1}"

Products

• VMware NSX

Issue/Introduction

• Logical Span port mirroring session has been configured on NSX to monitor the traffic from required source VMs.
• The source and destination group for the mirroring session consists of Virtual Network Interfaces.
• The session overall health under, NSX -> Plan & Troubleshoot -> Port Mirroring is healthy.
• However, checking further on the source group configured, its status is reported as failed.

• The failed source group reports the following Binding Status Error(s): 

Field level validation errors: {mirror_destination.port_ids has violated the minimum valid size 1}, {mirror_sources[0].port_ids has violated the minimum valid size 1}

• The source group satisfies Logical Span port mirroring session requirement that it should have a maximum of 6 virtual interfaces added statically.
• It was identified that the selected source VMs are connected to VLAN backed port groups and not overlay segments.

• However, logical span port mirroring sessions are supported only for overlay segments and not for VLAN segments/portgroups. For more information, please refer: Add a Port Mirroring Session

Environment

VMware NSX

Cause

The selected VM interfaces were not connected to overlay segments, which is a mandatory requirement for Logical Span port mirroring. As a result, these interfaces were deemed invalid for the port mirroring session.
Since this resulted in zero valid interfaces in the source group, NSX triggered a failure for violating the minimum valid source count (1).

Resolution

Please ensure that any VM selected as a source for a Logical Span port mirroring session is connected to an NSX Overlay segment.

If the source VMs are connected to VLAN segments or port groups, Logical Span is not supported. In this case, please configure the port mirroring session either directly on the vSphere Distributed Switch (VDS) or use the alternative port mirroring type, Remote L3 Span on NSX, which is compatible with VLAN-backed traffic.

Additional Information

For details on configuring port mirroring directly on a Distributed Switch, please refer the article: Create a Port Mirroring Session

For instructions on configuring port mirroring within NSX, please refer to: Add a Port Mirroring Session