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What Is BGP?

15.07.2026 Netbudur
What Is BGP?
Netbudur Blog Infrastructure, hosting and server guides

Internet Direction: What is BGP (Border Gateway Protocol) and How it Works?

Every day billions of people write a website address to the browser, watching videos or sending emails. So, how a data pack from your computer in Turkey goes to a server in America, and how to return from there to you in saliseler?

How do data packs find the right way to pass from millions of routers (router) across the world?

Here is the name of the protocol that organizes all this huge global traffic and is accepted as the Internet’s directional finding system (GPS) BGP (Border Gateway Protocol - Limit Pass Protocol)'dir.

1. What is BGP? Let's Understand With The Simpleest Benze

The Internet is not a single gigantic network. In fact, the internet is operated by tens of thousands of independent small networks (which are operated by telecom giants, data centers, universities and large tech companies (buna Otonom Sistem - Autonomous System / AS called) consists of a combination.

Otonom Sistemleri (AS) birer Countrya person who wants to travel between these countries as well as every data pack turist Let’s think.

  • You cannot find your way in a foreign continent without a map on your hand.

  • Here BGPstanding on the border gates of these countries and each other "If you want to go to America, you can pass from my above, my way is shorter and safer" The smart limit officers are like.

  • BGP connects even the most endpoints of the internet by enabling autonomous systems to exchange routes with each other.

2. How does BGP Work? (Technical Details)

BGP Path Vector (Road vector) protocol. Other internal network routing protocols (OSPF, EIGRP etc.) not only calculate the fastest or shortest physical way; analyzes relations, rules and policies between autonomous systems.

The basic working logic of BGP consists of these steps:

1. Neighborhood Relation (Peering)

BGP routers of two different networks have a secure connection with each other via TCP port 179. This processing BGP Peering called. The neighboring routers declare IP blocks (IP address pools) that they have each other.

2. Selecting the Best Path (Best Path Selection)

BGP considers many different criteria (BGP ⁇ s) while delivering a data package to the goal. Not only "short way" is always selected. The criteria are activated:

  • AS-Path: It is the number of autonomous systems that need to be passed to reach the target. It is preferable to pass at least AS.

  • Local Preference: It determines which road will be priority for traffic that goes out through a network.

  • MED (Multi-Exit Discriminator): An outside network is metric that you want to enter your network from which door.

3. BGP Types: What is iBGP and eBGP?

BGP is divided into two according to the location used:

  • eBGP (External BGP): Different autonomous systems (different companies/data centers). For example, Turkish Telecom’s router is installed with the communication eBGP between the router of a operator in Frankfurt.

  • iBGP (Internal BGP): The same autonomous system (the company) allows routers to share the BGP routes between them.

4. Why is BGP Important?

It could not be a "continent internet" as we know today. The critical advantages that BGP provides are:

⁇ 1. Seamless Connection (Redndancy)

Large data centers or service providers do not connect to the internet a single or even. They receive lines from multiple operators (Turkish Telecom, Cogent, Telia etc.). Thanks to BGP, one of these lines is automatically driven by the traffic milliseconds, when they break or fail. Even users do not feel downtime.

2. IP Anycast Teknolojisi

BGP lets you hear the same IP address from different servers across the world. This Anycast called. For example, when you use Cloudflare or Google DNS (8.8.8.8) address, BGP redirects you to the server in your physically closest (e.g. in Istanbul). This also minimizes ping times.

3. DDoS Protection (BGP Flowspec & RTBH)

A large cyber attack (DDoS) can be blocked or redirected to BGP redirects (null route) border gates with malicious traffic from the target IP address.

5. What Does BGP Collision? (Great Lessons From History)

BGP is so powerful that a small configuration error (misconfiguration) to do here can affect the whole world.

Unutulmaz Facebook Kesintisi (Ekim 2021): Facebook was the BGP error because Instagram and WhatsApp crashes all over the world for hours. Facebook engineers deleted BGP routes that accidentally goes to their DNS servers during a routine maintenance. Other routers on the Internet have seen Facebook as deleted from the map and did not access billions of people clock platforms.

Last Word: The Spine of the Internet BGP

In summary, BGP is a huge way finding system that allows data traffic to be lost on the internet, to achieve the most optimized, safest and most stable road target. Data centers are the most critical protocol that keeps hosting providers and telecom operators stand out.

If you want uninterrupted performance and accurate backup in your infrastructure, your BGP configuration is vital to be professionally done by expert hands!