To follow along with this chapter, you will need a PC that's capable of running pfSense. The specifications for such a PC will be discussed in detail in the section regarding hardware sizing guidelines, but in brief, you will need a PC with a 64-bit, AES-NI-capable processor, 1 GB of RAM, and 1 GB of storage. You may also run pfSense in a virtual machine if your PC meets these requirements.

Computer networking can be defined as an interconnection between two or more computers that allows the computers to share resources. This definition describes both the minimum requirement of having a network—at a minimum, there must be a physical means of connecting the computers—and the objective of networking, which is to share resources (examples include files, computational power, and many others).

At this point, we will introduce a conceptual model that will hopefully clarify a number of basic networking concepts—the Open Systems Interconnect (OSI) reference model. This model was created by the International Organization for Standards (ISO) in 1978...

Once you have decided to add a pfSense system to your network, you need to consider how it is going to be deployed on your network. pfSense is suitable for a variety of networks, from small to large ones, and can be employed in a variety of deployment scenarios. In this section, we will cover the following possible uses for pfSense:

• Perimeter firewall
• Router
• Switch
• Wireless router/wireless access point

As this book is aimed at beginner pfSense users, we will mainly focus on the first two items, as these are the most common uses of a pfSense device. We will, however, briefly discuss the latter two items.

The most common way to add pfSense to your network is to use it as a perimeter firewall. In this scenario, your internet connection is connected to one port on the pfSense system, and your local network is connected to another port on the...

Once you have decided where to deploy pfSense on your network, you should have a clearer idea of what your hardware requirements are. As a minimum, you will need a CPU, motherboard, memory (RAM), some form of disk storage, and at least two network interfaces (unless you are opting for a router on a stick setup, in which case you only need one network interface). You may also need one or more optional interfaces.

The starting point for our discussion on hardware requirements is pfSense's minimum specifications. As of January 2016, the minimum hardware requirements are as follows (these specifications are from the official pfSense site, https://www.pfsense...

You will also want to download the MD5 checksum file in order to verify the integrity of the downloaded image. Verifying the integrity of downloads serves two purposes:

• It ensures that the download completed
• It safeguards against a party maliciously tampering with the images

In order to safeguard against the latter, however, be sure to download the checksum from a different mirror site than the site from which you downloaded the image. This provides an additional measure of security should an individual mirror site be compromised. Windows has several utilities for displaying MD5 hashes for a file. Under BSD and Linux, generating the MD5 hash is as easy as typing the following command:

md5 pfSense-LiveCD-2.4.3-RELEASE-amd64.iso

This command will generate the MD5 checksum for the 64-bit Live CD version for pfSense 2.4.3. Compare the resulting hash with the contents...

If the installation was successful, you should see a screen similar to the one shown in the following screenshot:

Some of the initial configuration must be done at the console, while some aspects of the configuration, such as VLAN and DHCP setup, can be done from either the console or the web GUI. Configuration takes place in two phases. Some configuration must be done at the console, including interface configuration and interface IP address assignment. Some configuration steps, such as VLAN and DHCP setup, can be done both at the console and within the web GUI. On initial bootup, pfSense will automatically configure the WAN and LAN interfaces, according to the following parameters:

• Network interfaces will be assigned to device IDs em0, em1, and so on
• The WAN interface will be assigned to em0, and the LAN interface...

In this chapter, we began by discussing networking basics using the seven-layer OSI model as a point of departure. Although not an exhaustive tutorial on networking, the first section should help provide a basic idea of where pfSense fits into the structure of a typical network. We also covered typical pfSense deployment scenarios as well as the hardware requirements and sizing guidelines. We also covered how to download and install pfSense and how to perform basic system configuration using both the console and the Setup Wizard in the web GUI. Finally, we covered some additional setup options, and how to enable SSH login.

In the next chapter, we will cover how to complete pfSense configuration, including how to add interfaces, how to set up pfSense as a DHCP server, how to set up VLANs, and how to back up and restore your system.

1. Identify all seven layers of the seven-layer OSI model of networking.
2. (a) On what layer does the IP portion of the TCP/IP protocol suite reside? (b) On what layer does TCP reside?
3. Identify the ranges of the Class A, B, and C private networks.
4. Identify the three types of IPv4 addresses.
5. A desktop system has the following specifications. Can the current version of pfSense be installed onto it?
   • Pentium 4 1.8 GHz; 32-bit processor
   • 2 GB RAM
   • 250 GB IDE drive
   • DVD-ROM optical drive
6. Identify the file system options that are available when installing pfSense.
7. Under what circumstances is it possible to login to the pfSense console through the WAN port? Assume that SSH login has not yet been enabled.
8. If you configured both the WAN and LAN interfaces from the console, but you did not set up a DHCP server on the LAN interface, what additional step must be done if you want access...

• Hunt, C. (2002). TCP/IP network administration (3rd ed.). Sebastopol, CA: OReilly. Chapter 1, Overview of TCP/IP, provides a good summary of the seven-layer OSI model and the TCP/IP protocol architecture.
• Kurose, James F. and Ross, Keith W. (2000). Computer Networking: A Top-Down Approach Featuring the Internet. Boston: Addison Wesley. This book is organized around the seven-layer OSI model, so it is good supplemental reading for the part of this chapter which discusses that model.
• Y. Rekhter; B. Moskowitz; D. Karrenberg; G. J. de Groot; E. Lear (February 1996). Address Allocation for Private Internets (https://tools.ietf.org/html/rfc1918). Network Working Group IETF. This is the IETF's RFC defining private networks.