Understanding Border Gateway Protocol

Any form of transaction depends on rules, whether they're the basic rules of a spoken language or the routines established for a regular delivery route. The transfer of data over the Internet depends on a variety of protocols that govern how, when and where packets of data travel from one network to another, or from one point to another within the same network. One of the most helpful of these protocols is known as Border Gateway Protocol, or BGP. While this protocol is simpler in nature than, say, the TCP protocol that runs underneath it, it still poses some complexities that make it both tricky to understand and potentially easy to misuse. Let's take an introductory look at what BGP involves, how it works, and why you want your make sure your organization enjoys the highest standard of BGP implementation possible.

What Is Border Gateway Protocol?

Border Gateway Protocol serves as a master routing system for multiple networks or for components of a network. To get the central concept, it's useful to think of the Internet as a network made up of networks. Each of these networks is regarded as an autonomous system, or AS — and each AS may be constructed of multiple sub-networks linked together. There may be a great many possible pathways for routing data between any two AS networks, from a direct connection to lengthy detours that involve a number of "hops" through other AS networks. The Border Gateway Protocol takes into consideration both the number of "hops" and many other factors (including any monetary rates that one AS might charge another AS for route access), using a complex algorithm to determine the most efficient overall route for each data transfer.

External and Internal BGP

External BGP, or eBGP, functions just as described above. The protocol essentially plays the role of "postmaster general" in directing data transfers among the various "branch post offices" as represented by AS networks. An external BGP performs this function without regard for whatever internal protocol each AS is using to route data internally; it simply passes the data on as efficiently as it can, no matter what internal rules that data may follow. But it's also possible to make use of internal BGP, or iBGP, to perform similar services within a self-contained network. Internal BGP adds a critical extra degree of stability and security to any AS. This protocol can:

  • Greatly improve the quality and consistency of ISP service
  • Facilitate the use of MPLS VPN services
  • Make your organization's core network more stable
  • Respond quickly, efficiently and automatically to problems such as worms and Denial of Service attacks

The Importance of Proper Routing

BGP shares its tabled "maps" of network/AS pathways or routes, a process referred to as advertising. Unfortunately, BGP routes can be used to misdirect traffic instead of directing it properly — or this misdirection can occur entirely by accident. When a faulty or destructive BGP route is taken up by a large chunk of the Internet, the results can be catastrophic. One of the most visible and infamous examples occurred in 2008,when an ISP based in Pakistan manipulated BGP routing to prevent subscribers from accessing YouTube. But advertising these bad routes among multiple automated systems caused the routes to be taken up throughout the Internet, causing a global YouTube blackout. A BGP can also be vulnerable to criminal efforts, such as the 2018 "hijacking" of BGP routes that allowed attackers to reroute Amazon customer traffic — and funds, in the form of cryptocurrency — into their waiting hands.

These cautionary tales don't take away from the extraordinary stability and value of BGP; they only point toward the need to make sure that your organization is using this complicated protocol correctly. PS LIGHTWAVE offers state-of-the-art BGP services. Our fully bidirectional networks give you equally speedy data transfers for both uploads and downloads. Contact us today to speak with our skilled, experienced BGP experts.