Database
Risk: High
Port 9300 — Elasticsearch Cluster Transport Communication
Port 9300 is the internal cluster transport port utilized by Elasticsearch nodes to communicate, distribute shards, and execute master node elections.
PORT NUMBER
9300
PROTOCOL
TCP
DEFAULT PROCESS
java (elasticsearch)
FIREWALL TARGET
9300/tcp
Instant Terminal Fixes for Port 9300
macOS & Linux Terminal
1. Check who is listening on port 9300:
sudo lsof -i :9300 || sudo ss -tulpn | grep ":9300 "2. Kill process occupying port 9300 (EADDRINUSE fix):
sudo systemctl stop elasticsearch3. UFW Firewall Allow rule:
sudo ufw allow from 10.0.0.0/8 to any port 9300 proto tcpWindows PowerShell (Admin)
1. Check listening port:
Get-NetTCPConnection -LocalPort 93002. Force kill process on port 9300:
Stop-Service elasticsearch-service-x64 -Force3. Docker Port Forwarding Mapping:
docker run -d -p 9200:9200 -p 9300:9300 elasticsearch:8.12.0Common Error Encountered
NodeDisconnectedException: disconnected from node on port 9300.
Security Advisory & Hardening
Ensure xpack.security.transport.ssl is enabled so inter-node cluster data is encrypted across VPC networks.
Frequently Asked Questions
Port 9300 Questions & Answers
Common questions regarding default services, kill commands, and firewall configurations.
Port 9300 is commonly used for Elasticsearch Cluster Transport Communication. Port 9300 is the internal cluster transport port utilized by Elasticsearch nodes to communicate, distribute shards, and execute master node elections.