Firewalld block rancher cluster dns: Weave CNI does not work with Firewalld on RHEL 8 based OSs

This document (000020713) is provided subject to the disclaimer at the end of this document.


Firewalld service block Rancher cluster DNS on Rhel8.

Steps to reproduce:
     1. Install and setup RKE on RHEL 8
     2. CoreDNS is deployed as part of the RKE setup
     3. Start firewalld service on RHEL8 nodes.

After starting firewalld service, k8s pod logs return connection error:
ent-041273.voicelab.local. A: read udp> i/o timeout --------------


The Internal Kubernetes DNS server (coredns) is blocked. Once firewalld is stopped, the Kubernetes DNS works well.

Firewalld block these ports that are required:

- 2379-2380/tcp
- 4789/udp
- 5000/tcp
- 6443/tcp
- 6783/tcp
- 6783-6784/udp
- 9100/tcp
- 10250/tcp
- 10257/tcp
- 10259/tcp


Stop firewalld on RHEL8 nodes, it is a requirement as described in Rancher requirements:


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  • Document ID:000020713
  • Creation Date: 11-Oct-2022
  • Modified Date:11-Oct-2022
    • SUSE Rancher

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