DevOps & Cloud
Risk: Low
Port 9100 — Prometheus Node Exporter
Port 9100 is the standard HTTP scraping metrics port for Prometheus Node Exporter, publishing real-time host CPU, memory, disk, and network stats.
PORT NUMBER
9100
PROTOCOL
TCP
DEFAULT PROCESS
node_exporter
FIREWALL TARGET
9100/tcp
Instant Terminal Fixes for Port 9100
macOS & Linux Terminal
1. Check who is listening on port 9100:
curl -s http://localhost:9100/metrics | head -n 102. Kill process occupying port 9100 (EADDRINUSE fix):
sudo systemctl stop node_exporter || kill -9 $(lsof -t -i:9100)3. UFW Firewall Allow rule:
sudo ufw allow from 10.0.0.0/8 to any port 9100 proto tcpWindows PowerShell (Admin)
1. Check listening port:
Get-NetTCPConnection -LocalPort 91002. Force kill process on port 9100:
Stop-Process -Name node_exporter -Force -ErrorAction SilentlyContinue3. Docker Port Forwarding Mapping:
docker run -d -p 9100:9100 prom/node-exporterCommon Error Encountered
Prometheus server scraping error: dial tcp :9100: connect: connection refused.
Security Advisory & Hardening
Node Exporter outputs detailed server hardware specs and kernel details. Restrict scraping to authorized Prometheus server IPs.
Frequently Asked Questions
Port 9100 Questions & Answers
Common questions regarding default services, kill commands, and firewall configurations.
Port 9100 is commonly used for Prometheus Node Exporter. Port 9100 is the standard HTTP scraping metrics port for Prometheus Node Exporter, publishing real-time host CPU, memory, disk, and network stats.