Pod to Pod/Node connections not working for application specific port while using Antrea CNI

Products

• VMware vSphere Kubernetes Service
• VMware Container Networking with Antrea

Issue/Introduction

• The environment was migrated from TKGM (Tanzu Kubernetes Grid multi-Cloud) to TKGS (Tanzu Kubernetes Grid Service), prior to the migration, the pod to pod/node connection was working.
• Antrea is deployed as the CNI (Container Network Interface) and using encap mode.
• TKGS is deployed with hostNetwork: true

Environment

Antrea

TKGS

VKS (vSphere Kubernetes Service)

Cause

The node's iptables does not permit the port which is being used for the application.

Please review this KB for details on the allowed ports Pod to pod communication isn't working when setting deployment's hostNetwork setting to true

Resolution

Ensure the application uses ports within the range listed.