LWM-Linux/13 - Linux Performance Monitoring and Tuning/Linux Network Performance Tuning.md

Linux Network Performance Monitoring

Linux Network Performance Monitoring: A Comprehensive Guide

1. Introduction

• Importance of network performance monitoring
• Overview of Linux tools and techniques

2. Key Network Performance Metrics

• Bandwidth
• Latency
• Packet loss
• Throughput
• Jitter
• Connection states

3. Built-in Linux Commands for Network Monitoring

ping

  - Basic usage and interpretation
  - Advanced options (interval, packet size, flood ping)

traceroute / tracepath

  - Tracing network path and identifying bottlenecks
  - Understanding output and hop analysis

netstat

  - Monitoring network connections and routing tables
  - Useful options and real-time monitoring

ss (Socket Statistics)

  - Modern replacement for netstat
  - Monitoring TCP, UDP, and UNIX socket connections

ip

  - Configuring and monitoring network interfaces
  - Viewing routing information and ARP cache

4. Advanced Command-line Tools

iftop

  - Real-time bandwidth usage monitoring per connection
  - Installation and usage guide

iptraf

  - Interactive colorful IP LAN monitor
  - Detailed statistics on various network protocols

nethogs

  - Monitoring per-process network usage
  - Identifying bandwidth-hungry applications

tcpdump

  - Packet capture and analysis
  - Filtering options and output interpretation

nload

  - Monitoring network traffic and bandwidth usage in real-time
  - Graphical representation in the terminal

5. System-wide Monitoring Tools

Nagios

  - Overview and setup
  - Configuring network performance checks
  - Alerts and notifications

Zabbix

  - Installation and configuration
  - Creating network monitoring templates
  - Visualization and reporting

Prometheus + Grafana

  - Setting up Prometheus for metrics collection
  - Configuring Grafana dashboards for network visualization
  - Creating custom alerts

6. Specialized Network Monitoring Tools

Wireshark

  - GUI-based packet analyzer
  - Capture and analysis techniques
  - Protocol-specific analysis

nmap

  - Network discovery and security auditing
  - Port scanning and OS fingerprinting

iperf / iperf3

  - Network performance testing
  - Measuring maximum achievable bandwidth

7. Kernel Tuning for Network Performance

sysctl parameters

  - TCP/IP stack optimization
  - Buffer sizes and connection handling

Network interface configuration

  - MTU optimization
  - TCP segmentation offload (TSO)
  - Interrupt coalescing

8. Log Analysis for Network Performance

• Important log files (/var/log/syslog, /var/log/messages)
• Using tools like logwatch and fail2ban
• Centralized logging with ELK stack (Elasticsearch, Logstash, Kibana)

9. Automating Network Performance Monitoring

• Writing shell scripts for regular checks
• Using cron jobs for scheduled monitoring
• Developing custom monitoring solutions with Python

10. Best Practices

- Establishing baselines
- Regular performance audits
10.3. Documentation and change management
10.4. Capacity planning

11. Troubleshooting Common Network Performance Issues

- High latency
- Packet loss
- DNS resolution problems
- Bandwidth saturation
- Network congestion

12. Case Studies

- Identifying a network bottleneck in a web server setup
- Troubleshooting intermittent connectivity issues
- Optimizing network performance for a large-scale database cluster

13. Future Trends in Linux Network Performance Monitoring

- AI/ML-based anomaly detection
- Container and microservices monitoring
- Cloud-native monitoring solutions

14. Conclusion

- Recap of key points
- Importance of continuous monitoring and optimization