BGP Implementation Example

In Figure 7-12, BGP is used to interconnect multiple autonomous systems. Because of the multiple connections between autonomous systems and the need for path manipulation, the use of static routing is excluded. AS 65000 is multihomed to three ISPs: AS 65500, AS 65250, and AS 64600.

Figure 7-12 BGP Is Used to Interconnect Autonomous Systems

Figure 7-12 BGP Is Used to Interconnect Autonomous Systems

NOTE The AS designator is a 16-bit number with a range of 1 to 65535. RFC 1930, Guidelines for Creation, Selection, and Registration of an Autonomous System (AS), provides guidelines for the use of AS numbers. A range of AS numbers, 64512 to 65535, is reserved for private use, much like the private IP addresses. All the examples in this book use private AS numbers to avoid publishing AS numbers belonging to an organization. An organization must use an Internet Assigned Numbers Authority-assigned AS number rather than a private AS number only if it plans to use an EGP, such as BGP, to connect to a public network such as the Internet. On the Internet, ISPs use public AS numbers.

Was this article helpful?

0 0

Post a comment