"IP Block CIDRs ['###.#.##.##/##] due to overlapping with existing ones." error reported in NSX NCP logs in a VKS environment

Products

• VMware NSX

Issue/Introduction

• If the NCP service is restarted in a VKS (vSphere Kubernetes Service), the NCP logs displays the following:

[ncp GreenThread-128 W] nsx_ujo.ncp.nsx.policy.project_service Ignoring Namespace overlap-test-ns IP Block CIDRs ['<ip_address>/<prefix>'] due to overlapping with existing ones.
[ncp GreenThread-128 I] nsx_ujo.ncp.k8s.nsx_network_config_controller Successfully synced Namespace Ingress pool with CIDR ['<ip_address>/<prefix>'] for Namespace overlap-test-ns(########-56a7-4c81-b3df-############)
[ncp GreenThread-128 W] nsx_ujo.ncp.nsx.policy.project_service Ignoring Namespace overlap-test-ns IP Block CIDRs ['<ip_address>/<prefix>'] due to overlapping with existing ones.
[ncp GreenThread-128 I] nsx_ujo.ncp.k8s.nsx_network_config_controller Successfully synced Namespace Egress pool with CIDR ['<ip_address>/<prefix>'] for Namespace overlap-test-ns(########-56a7-4c81-b3df-############)

• No impact is observed and VKS is functioning properly.
• During VKS deployment in vCenter, the Supervisor default configuration was overridden and bespoke networking was used, rather than the default for ingress/egress/pod networking.

Environment

VMware NSX

VKS

Cause

This is a False Positive and has no impact, the first log line gives the warning about overlapping IP Block, but then immediately after, successfully synced the namespace, this only occurs when the Supervisor default configuration is overridden during deployment.

Resolution

No workaround is required, the log is a false positive.