DIY AS: FreeBSD, FRR, and BGP for Network Control

The New Frontier of the Internet: Personal Autonomous Systems

The internet typically flows through infrastructures controlled by large telecommunications companies and content providers. However, technology enthusiasts and network freedom advocates are exploring ways to become part of the global internet backbone from their homes or small offices as an alternative to this centralized structure. At the core of this movement lies acquiring your own Autonomous System (AS) number and running Border Gateway Protocol (BGP) routing on a personal server.

An AS number represents a set of IP addresses managed under a single routing policy on the internet. Traditionally, these numbers are allocated to large companies, universities, and service providers. However, through Regional Internet Registries (RIRs), individuals and small communities can also register their own AS if they meet certain requirements. This step is seen as a critical milestone in the internet's evolution toward a decentralized, more democratic future.

Setting Up a BGP Router with FreeBSD and FRR

The technical heart of creating your own AS is a server capable of running BGP software reliably. FreeBSD is an operating system frequently chosen for this purpose due to its security, stability, and advanced network stack features. On top of it, FRR (Free Range Routing), an open-source and powerful routing software suite, is installed.

FRR supports various routing protocols like BGP, OSPF, RIP and can be configured via a command-line interface. The user defines their own AS number, neighboring ASes (typically a transit or peering provider), and which IP prefixes to advertise to these neighbors by editing FRR configuration files. This process translates the operation performed with professional equipment in a large data center to a personalized environment using software-defined networking (SDN) logic.

Establishing Connectivity: GRE Tunnels and Policy-Based Routing

Home or office environments usually have a single broadband connection where BGP peering is not permitted. To overcome this obstacle, GRE (Generic Routing Encapsulation) tunnels are used. A GRE tunnel encapsulates an IP packet within another IP packet, creating a virtual private connection between two points. The user establishes a GRE tunnel between a cloud server (VPS) or a supporting friend's server and their own FreeBSD server. Thus, BGP traffic can flow over this tunnel without being affected by the broadband provider's policies.

Policy-based routing is the brain center of this setup. It decides which traffic will be routed via the normal internet connection and which via the GRE tunnel, and consequently through the personal AS. For example, traffic to a specific server or service can be routed through the personal network to enhance privacy or provide redundant connectivity. This is made possible by the operating system's core network management tools. Similarly, tools like File Explorer in Windows 11 allow users to organize and search files and resources on their own systems, forming an important part of personal infrastructure management.

The Meaning of a Free and Scalable Network

The philosophy behind this technical effort is the quest to return to the internet's original decentralized spirit. Having your own AS means:

• Independence: You can operate largely independently of your internet service provider's routing policies.
• Flexibility: You can establish connections with multiple service providers and route your traffic based on performance or cost.
• Community Networks: By establishing direct network connections (peerings) with like-minded individuals, you can divert your traffic away from large commercial backbones, creating a faster and more resilient local communication network.