Nagios Port Numbers & Protocols: Default & Custom Configurations

Introduction to Nagios Ports & Network Communication

This guide provides Nagios Network Administrators with essential details on the ports and protocols used by Nagios XI, ensuring seamless network monitoring and efficient server configurations. Whether you’re troubleshooting connectivity or planning a deployment, this guide covers everything you need to know.

View the PDF Version: Nagios-Ports-and-Protocols.pdf

How Nagios Uses Ports & Protocols for Monitoring

Nagios XI relies on various ports and protocols to communicate effectively across networks. Understanding these is crucial for optimal system performance and secure configurations.

Port Configuration & Customization

1. Customizable Ports: While Nagios XI has default port configurations, administrators can modify these to meet specific network requirements.
2. Plugin-Specific Needs: Nagios XI supports a wide range of plugins, each with its own port requirements, making it essential to tailor your configuration to your monitoring environment.

Default Ports & Protocols

Web Access: HTTP & HTTPS (Ports 80, 443)

• Purpose: Enables web-based access to the Nagios XI interface.
• Details: HTTP operates on port 80, while HTTPS uses port 443 for secure communication. HTTPS is highly recommended for protecting sensitive data.

SNMP Monitoring (Ports 161, 162)

• Purpose: Facilitates network device monitoring.
• Details: Port 161 handles SNMP requests, while port 162 receives SNMP traps, offering extensive visibility into network performance.

Remote Access: SSH (Port 22)

• Purpose: Provides secure remote access to Linux-based systems monitored by Nagios XI.
• Details: Essential for executing remote commands and scripts.

File Transfers: FTP (Port 21)

• Purpose: Used for transferring backups and plugins.
• Details: Although FTP operates on port 21, secure alternatives like SFTP or FTPS are recommended to enhance data security.

Nagios Plugins & Their Required Port Numbers

Plugin / Service	Default Ports(s)
check_nt (NSClient++)	12489
Email (SMTP)	25,465,587
MongoDB	27017, 27018, 27019, 27020
MSSQL	1433
MySQL	3306
NCPA	5693
NRPE	5666
NSCA	5667
OracleDB	1521
PostgreSQL	5432
WebLogic	7001, 9090
WMI	135, 445 (dynamic ports: 1024–1034)

Note: Ensure that these ports are open and properly configured in your network firewall to allow smooth communication for Nagios XI and its plugins.

Additional Resources

• Nagios Support Forums: Visit Here
• Nagios Knowledgebase: Explore Here

For more details on Nagios XI and its configuration, explore the above resources or contact Nagios support.