What is BGP Protocol?
What is Cybersecurity?
Cyber Security refers to the practice of protecting users, devices, networks, and programs from digital attacks. These cyberattacks are usually aimed at accessing, changing, or destroying sensitive information, extorting money from users, or interrupting normal business operations. Implementing effective cybersecurity measures is particularly challenging today because there are more devices than people, and attackers are becoming more innovative.
What is Dedicated Internet Access? (DIA)
The Border Gateway Protocol (BGP) is a standardised and path-vector routing protocol used to facilitate communication between different networks across the internet. It operates by exchanging routing information between autonomous systems (AS)—independent networks managed by ISPs, enterprises, or data centres—ensuring that data packets are efficiently directed to their correct destinations.
Unlike traditional routing protocols, BGP dynamically selects the best available path based on factors like network policies, path length, and reliability. It continuously updates routes in response to network changes, making it highly adaptable and essential for internet stability.
BGP is widely used by internet service providers (ISPs), cloud providers, enterprises, and large-scale data centres to manage internet traffic efficiently. Since it enables seamless global connectivity and optimises routing decisions, BGP is often referred to as the "backbone of the internet." Without BGP, large-scale communication between different networks would be inefficient, leading to slow data transfers and connectivity issues.
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How Does BGP Work?
BGP is a path-vector routing protocol that enables efficient and reliable communication between different networks by determining the best routes for data transmission. It operates over Transmission Control Protocol (TCP) port 179 and ensures that internet traffic is directed through the most optimal paths. The process involves:
Path Selection
BGP evaluates multiple routes based on attributes like AS Path, Local Preference, and Multi-Exit Discriminator (MED) to determine the most efficient route.
Routing Information Exchange
BGP routers establish peer connections and exchange network reachability information, ensuring all participating networks are aware of the available paths.
Dynamic Updates
Unlike static routing, BGP continuously monitors network conditions and automatically updates routing tables when a better or more reliable path becomes available, preventing disruptions and improving overall network performance.
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Types of BGP
Border Gateway Protocol (BGP) is broadly categorised into two types based on its scope of operation—whether it is used for inter-network communication or to manage routing within a single organisation. Both types play a crucial role in maintaining stable and efficient internet routing.
External BGP (eBGP)
eBGP is used for routing between different autonomous systems (ASes). It facilitates the exchange of routing information between internet service providers (ISPs), data centres, cloud providers, and large enterprises.
- eBGP routers typically connect directly to routers in other ASes and share prefix advertisements (IP address blocks they can reach).
- It plays a critical role in global internet routing, enabling the interconnection of thousands of networks.
- eBGP routers often have different administrative distance values and rely on policies to determine which routes to accept or advertise.
- Since eBGP routes are learned externally, they must pass through strict filtering and security policies to prevent route leaks or malicious traffic redirections.
Internal BGP (iBGP)
iBGP operates within a single autonomous system, ensuring that all routers in an AS have a consistent and synchronised view of external routes.
- Unlike eBGP, iBGP routers do not change the AS Path attribute when propagating routes, preventing routing loops within the AS.
- iBGP requires a full mesh topology, meaning each router must be manually configured to establish direct BGP sessions with all other iBGP routers. This complexity is often reduced by using route reflectors and BGP confederations.
- It is crucial for large enterprises, ISPs, and cloud providers managing multi-data centre networks and ensuring seamless internal traffic routing.
Both eBGP and iBGP are essential for maintaining the efficiency, reliability, and scalability of modern network infrastructures, ensuring seamless connectivity across both local and global networks.
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BGP Attributes and Path Selection
BGP does not rely on traditional shortest-path algorithms like other routing protocols. Instead, it uses a set of attributes to determine the most efficient and reliable path for routing data across networks. These attributes help BGP routers make intelligent routing decisions based on policies rather than just distance.
AS Path
- The Autonomous System (AS) Path records the sequence of ASes a route passes through before reaching its destination.
- This attribute helps prevent routing loops, as a router can reject routes that already contain its own AS number.
- Shorter AS Paths are generally preferred, but network policies can override this default behaviour.
Next Hop
- The Next Hop attribute identifies the next router in the path that should receive the packet.
- In eBGP, the next hop is usually the router in the neighbouring AS, whereas in iBGP, the next hop remains unchanged unless modified by network policies.
- Proper configuration of the Next Hop attribute is crucial to avoid routing inconsistencies.
Local Preference
- Local Preference is a numerical value assigned to routes within an AS to control outbound traffic flow.
- A higher Local Preference value indicates a more preferred route.
- It is primarily used in iBGP to ensure traffic exits the AS through the most desirable path, such as selecting a primary ISP over a backup provider.
Multi-Exit Discriminator (MED)
- The Multi-Exit Discriminator (MED) is an optional attribute that suggests a preferred inbound path to neighbouring ASes.
- It is used when two ASes have multiple interconnection points, helping to optimise inbound traffic distribution.
- Unlike Local Preference, which influences outbound traffic, MED is a recommendation rather than a strict rule—other ASes can choose whether to honour it.
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Importance of BGP in Network Performance
BGP plays a critical role in ensuring the stability, efficiency, and scalability of the internet. It dynamically manages traffic routing across multiple networks, adapting to changes in real time to maintain optimal performance.
Traffic Optimisation
- BGP continuously evaluates network conditions and selects the most efficient path for data transmission.
- It factors in latency, congestion, and link failures, rerouting traffic to prevent bottlenecks.
- This is particularly useful for content delivery networks (CDNs) and cloud services that rely on fast and efficient data transfers.
Redundancy and Failover
- BGP ensures high availability by maintaining multiple paths to the same destination.
- If one route fails due to a network outage, maintenance, or cyberattack, BGP automatically reroutes traffic through alternative paths.
- This feature is essential for enterprises, ISPs, and data centres that require continuous network uptime.
Scalability
- BGP can handle millions of IP prefixes, making it suitable for large-scale global networks.
- Unlike traditional routing protocols that struggle with high-volume route processing, BGP efficiently aggregates and filters routes to reduce complexity.
- This makes BGP indispensable for internet service providers (ISPs), multinational corporations, and cloud platforms that operate vast, distributed networks.
By ensuring efficient traffic flow, network redundancy, and seamless scalability, BGP enhances overall internet performance, supporting the needs of both small enterprises and large-scale global networks.
Orixcom's Implementation of BGP Protocols and Scalability Features
Orixcom leverages the strengths of BGP to provide robust and scalable network solutions:
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Reliable International IP Transit: A global IP backbone ensures seamless connectivity and superior performance, offering businesses uninterrupted global internet access.
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Flexible Bandwidth Options: With connectivity options ranging from 1 GE to 100 GE enables catering to diverse networking requirements, facilitating high-speed data transfer and seamless communication across multiple devices.
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Robust Service Level Agreements (SLAs): Orixcom provides a 99.999% SLA, ensuring reliability and performance.
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Burstable Options: To accommodate dynamic network demands, Orixcom offers burstable options, ensuring scalability and flexibility in their IP Transit services.
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Maximum Service Reliability: With dedicated 24x7x365 monitoring, Orixcom guarantees uninterrupted connectivity and proactive support, ensuring maximum service reliability.
Challenges and Security Risks of BGP
Despite being a foundational protocol for internet routing, BGP was not originally designed with security in mind. As a result, it is vulnerable to misconfigurations, malicious attacks, and performance issues, which can impact network reliability and data security.
BGP Hijacking
- In a BGP hijacking attack, a malicious entity advertises false routes, tricking networks into sending traffic through unauthorised paths.
- This can result in traffic interception, data theft, or large-scale service disruptions.
- High-profile incidents, such as hijacks affecting financial institutions and global service providers, have exposed the critical need for securing BGP announcements.
Route Leaks
- Route leaks occur when an autonomous system (AS) mistakenly advertises routes it should not, either due to misconfiguration or intentional actions.
- This can lead to suboptimal routing, increased latency, or even network outages.
- A well-known case occurred in 2018, when a misconfiguration by an ISP rerouted Google’s traffic through an unintended network, causing widespread disruption.
Slow Convergence
- When network changes occur, BGP takes time to update its routing tables, leading to temporary connectivity issues.
- Unlike other routing protocols that update almost instantly, BGP follows a deliberate, incremental update process to avoid instability.
- This delay can impact real-time applications, such as video streaming, financial transactions, and cloud services.
These challenges highlight the need for improved BGP security measures, including route filtering, cryptographic validation (RPKI), and real-time monitoring to protect against attacks and optimise network stability.
How to Secure and Optimise BGP?
Since BGP lacks built-in security mechanisms, it is essential to implement protective measures to prevent route hijacking, leaks, and misconfigurations. The following security best practices help ensure a stable and resilient BGP infrastructure.
Route Filtering
- Restricts the advertisement and acceptance of BGP routes, preventing unauthorised or erroneous routes from disrupting the network.
- Network administrators define specific prefixes and AS paths that are allowed or denied preventing malicious route propagation.
BGP Prefix Filtering
- Ensures routers only accept valid prefixes from authorised sources, reducing the risk of route leaks and accidental misconfigurations.
- Organisations can use tools like IRR (Internet Routing Registry) databases to maintain an authorised list of prefixes.
RPKI (Resource Public Key Infrastructure)
- A cryptographic method for validating BGP route announcements, ensuring that only legitimate ASes advertise specific IP prefixes.
- Helps protect against BGP hijacking, where attackers attempt to reroute traffic by announcing fake prefixes.
- Major ISPs and cloud providers are increasingly adopting RPKI to strengthen routing security.
BGP Monitoring Tools
- Solutions like BGPMon, RIPE Atlas, and ThousandEyes help detect suspicious routing behaviour, unauthorised route advertisements, and performance issues.
- Continuous real-time monitoring allows quick response to BGP anomalies, reducing the impact of hijacks or leaks.
By combining these security techniques, organisations can reduce BGP vulnerabilities, enhance routing stability, and safeguard internet infrastructure from cyber threats and operational risks.
Contributors:

Anthony Grower
Topic Specialist

Kelly Brighton
Topic Specialist

Richard Peace
Topic Specialist
Sources:
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Autonomous System (AS)
A collection of IP networks and routers that operate under a single, unified routing policy, identified by a unique Autonomous System Number (ASN). Each AS is managed by an organisation, such as an ISP, cloud provider, or enterprise network, and uses BGP to exchange routing information with other ASes.
Routing Table
A database stored within a router or network device that contains information about available network routes. It determines the best path for forwarding packets based on metrics like hop count, AS path, and routing policies, ensuring efficient data transmission across the internet.
Anycast
A networking technique where multiple servers share the same IP address, allowing requests to be routed to the nearest available server. This improves latency, load balancing, and redundancy, making it widely used in content delivery networks (CDNs), DNS services, and DDoS protection.
IP Peering
A direct interconnection between two or more networks, allowing them to exchange traffic without relying on a third-party transit provider (ISP). Peering improves network performance, reduces costs, and lowers latency by enabling faster, more efficient data routing between participating networks.
Multiprotocol BGP (MP-BGP)
An extension of BGP that supports routing for multiple network protocols, including IPv4, IPv6, and MPLS VPNs. MP-BGP enables service providers to manage layer 3 VPNs, multicast routing, and IPv6 adoption efficiently within a single BGP session.