UDP 5405
Synopsis
- Corosync (the cluster communication/membership engine, formerly OpenAIS) uses UDP port 5405 by default for cluster traffic (often alongside UDP 5404).
- Pacemaker-based Linux HA stacks rely on this, including Red Hat Enterprise Linux High Availability Add-On, SUSE Linux Enterprise High Availability Extension, and Ubuntu/Debian Pacemaker/Corosync clusters.
- Proxmox VE clusters use Corosync for quorum and messaging, thus using UDP 5405 between Proxmox nodes.
- Older Red Hat Cluster Suite (CMAN/OpenAIS) deployments also used UDP 5405 for cluster communication.
- Many distributions’ firewall presets (e.g., firewalld’s “high-availability” service) explicitly open UDP 5404–5405 for Corosync traffic.
Observed activity
Last 30 days
Detailed chart