Information Technology Reference
In-Depth Information
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Advanced BGP Introduction
Border Gateway Protocol (BGP)
is a routing protocol that is used to exchange network
layer reachability information (NLRI) between routing domains. A routing domain is often
called an
autonomous system (AS)
because different administrative authorities control their
respective domains. The current Internet is a network of interconnected autonomous
systems, where BGP version 4 (BGP4) is the de facto routing protocol.
Understanding BGP Characteristics
The Internet has grown significantly over the past several decades. The current BGP table
in the Internet has more than 100,000 routes. Many enterprises have also deployed BGP to
interconnect their networks. These widespread deployments have proven BGP's capability
to support large and complex networks.
The reason BGP has achieved its status in the Internet today is because it has the following
characteristics:
•
Reliability
•
Stability
•
Scalability
•
Flexibility
The following sections describe each of these characteristics in more detail.
Reliability
You can examine BGP's reliability from several perspectives:
•
Connection establishment
•
Connection maintenance
•
Routing information accuracy
