Protecting Your Network with Open-Source Software

Introduction

• Protect your network with free and open-source software
• What you should know
• Environment setup

1. Understanding Open-Source Software

• What is open-source software?
• Open-source software in networking
• Open-source solutions in cybersecurity
• Open-source vs. commercial software
• Costs and savings

2. Firewalls

• What is a firewall?
• Host firewalls
• Network firewalls
• Static packet filtering vs. stateful packet inspection
• Challenge: Disable UFW
• Solution: Disable UFW

3. Host as a Router

• Netfilter and iptables
• Setting up a host firewall using iptables
• Automating netfilter configuration
• Understanding hosts as routers
• Adding a network adapter
• Testing the second adapter
• Setting up IP forwarding
• Changing netfilter settings: Part 1
• Changing netfilter settings: Part 2
• Testing the router

4. Host as a Network Firewall

• Setting up hosts as network firewalls
• Setting up a web server
• Port forwarding
• Testing port forwarding
• Understanding one-legged DMZ
• Understanding true DMZ
• Understanding an application proxy firewall
• Setting up Squid
• Challenge: Fine-tuning the Squid configuration
• Solution: Fine-tuning the Squid configuration

5. Packet Analysis

• What is packet analysis?
• ARP poisoning example
• Packet capturing with Wireshark
• Exploring Wireshark's advanced features
• Wireshark hands-on
• Challenge: Filtering with IP addresses and port numbers
• Solution: Filtering with IP addresses and port numbers

6. IDSs and Vulnerability Assessment

• What is an IDS?
• Introducing Snort
• Snort as a packet sniffer
• Snort as an IDS: Establishing rules
• Snort as an IDS: Detecting pings
• What is a network vulnerability assessment?
• Nessus
• Network scanning with Nessus

7. Logging and Monitoring

• Logging
• syslog-ng
• Log forwarding: Part 1
• Log forwarding: Part 2
• Kiwi
• SNMP

Conclusion

• Next steps