StatsD Admin / Datadog APM
What is Port 8126?
Port 8126 is used by StatsD for its TCP admin interface and by the Datadog Agent for receiving APM (Application Performance Monitoring) traces. The StatsD admin port allows management commands for the StatsD daemon. Datadog's trace agent listens on port 8126 for distributed tracing data from instrumented applications. When using Datadog APM, application libraries send trace data to the local Datadog Agent on this port, which then forwards it to Datadog's cloud platform. This is a critical port for Datadog-instrumented applications.
Common Uses
- Datadog APM trace collection
- StatsD administrative interface
- Distributed tracing data reception
- Application performance monitoring
Technical Details
Copy-paste commands to check port 8126 (StatsD Admin / Datadog APM) from your terminal
Test connectivity
nc -zv example.com 8126
curl -v --max-time 5 http://example.com:8126/
telnet example.com 8126
nmap -p 8126 -sV example.com
(echo > /dev/tcp/example.com/8126) 2>/dev/null && echo "open" || echo "closed"
Open port in firewall
sudo ufw allow 8126/tcp
sudo iptables -A INPUT -p tcp --dport 8126 -j ACCEPT
sudo firewall-cmd --permanent --add-port=8126/tcp && sudo firewall-cmd --reload
Security Considerations
Restrict port 8126 to localhost or the local network. The Datadog Agent should only accept traces from authorized applications. In Kubernetes, configure the agent as a DaemonSet with appropriate network policies.
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