Some VCS components do not work on the systems where a firewall is configured to block TCP traffic (3545338)

Last published : Sep 18, 2026
The following issues may occur if you install and configure VCS on systems where a firewall is installed:
  • If you set up Disaster Recovery using the Global Cluster Option (GCO), the status of the remote cluster (cluster at the secondary site) shows as "initing".
  • If you configure fencing to use CP server, fencing client fails to register with the CP server.
  • Setting up trust relationships between servers fails.
Workaround:
  • Ensure that the required ports and services are not blocked by the firewall. Refer to the Cluster Server Configuration and Upgrade Guide for the list of ports and services used by VCS.
  • Configure the firewall policy such that the TCP ports required by VCS are not blocked. Refer to your respective firewall or OS vendor documents for the required configuration.
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