Class 4- Intro to Firewalls

Intro to Firewalls

Intro to Small Home Networking

Key Vocabulary and Concepts

  • NIC
  • DHCP
    • DHCP vs Static IP assignment
    • DHCP reservation
  • Ports
  • Switch Vs Router
  • Gateway 
  • LAN  local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building and has its network equipment and interconnects locally managed
  • WAN – a telecommunications network or computer network that extends over a large geographical distance.
  • VLAN – A virtual LAN (VLAN) is any broadcast domain that is partitioned and isolated in a computer network at the data link layer (OSI layer 2).
  • DMZ- In computer security, a DMZ or demilitarized zone (sometimes referred to as a perimeter network) is a physical or logical subnetwork that contains and exposes an organization’s external-facing services to an untrusted network, usually a larger network such as the Internet.
  • DNS – is a hierarchical decentralized naming system for computers, services, or other resources connected to the Internet or a private network.
  • Internal VS external IP address
  • NAT -Network address translation (NAT) is a method of remapping one IP address space into another by modifying network address information in Internet Protocol (IP) datagram packet headers while they are in transit across a traffic routing device.
  • Port forwarding – port forwarding or port mapping is an application of network address translation (NAT) that redirects a communication request from one address and port number combination to another while the packets are traversing a network gateway, such as a router or firewall.

Network Diagrams

    1. Why they are a good tool
    2. Examples

Intro to Firewalls

  1. What is a firewall?
  2. Why would I want to use one?
    1. Extra Security
    2. VPN
    3. Packet inspection
    4. Restricting connections to your home network

Workshop Portion:

What do I need to build one at home (bare minimum)?

pfSense install

  • Initial Rule Configuration
  • Block vs Reject
  • Some basic rules to add in:
  • Port Blocking
  • Country Blocking
  • pfBlocker
  • Known bad IP blocking
  • SquidGaurd

Useful command line commands

  • Ping
  • ifconfig/ipconfig

Resources for advanced configuration, tips, tricks and troubleshooting.


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