BGP Peering refers to the process by which two networks agree to directly exchange routing information using the Border Gateway Protocol (BGP). BGP is the protocol that underpins the routing architecture of the internet, allowing Autonomous Systems (AS) to share routes and reachability information with each other. An Autonomous System is a collection of IP routing prefixes under the control of one or more network operators that presents a common routing policy to the internet.
There are two main types of BGP Peering:
- Public Peering: This occurs at Internet Exchange Points (IXPs) where multiple networks connect and exchange traffic. Public peering allows for the efficient exchange of traffic but may not be suitable for very high volumes of traffic due to potential congestion at the peering points.
- Private Peering: This is established when two networks connect directly, typically through a dedicated IP connection, often in a colocation facility. Private peering is preferred for exchanging large volumes of traffic as it can provide a more reliable and secure connection.
BGP Peering involves configuring BGP sessions between routers in each network. These sessions are used to exchange routing information, such as which IP addresses are reachable through each network. The configuration of BGP on both sides of the connection determines whether it is a peering or internet access/transit relationship.
The benefits of BGP Peering include:
- Security: Direct connections can reduce the risk of data sniffing and internet-based exploits.
- Performance: Peering can offer better performance due to controlled latency and capacity between the two parties.
- Reliability: Direct connections can be more reliable than routing traffic over the internet.
To set up BGP Peering, a network needs an Autonomous System Number (ASN) and its own public IP address space. Peering agreements are typically negotiated between the parties involved, and once an agreement is reached, the necessary physical or virtual connections are established, and BGP sessions are configured.
In summary, BGP Peering is a critical component of internet connectivity that allows networks to directly exchange routing information, improving security, performance, and reliability of data transmission between them.