Introduction of routing protocol and BGP room

1. Route Selection Protocol

The core of routing protocol is routing algorithm, the router uses routing protocol to generate routing table, which can realize the "best" path of the network packets.

2. Classification of routing protocols

Routing protocol is divided into internal Gateway Protocol IGP and External Gateway protocol EGP two kinds. The internal gateway protocol is used in the autonomous system's internal routing, the external gateway protocol is used in the autonomous system routing, to achieve the interconnection between autonomous systems.

(1) Internal Gateway Protocol IGP

Internal Gateway Protocol IGP RIP, OSPF and so on.

(2) External Gateway Protocol EGP

External Gateway protocol EGP has BGP and so on.

3.BGP Room

BGP is mainly used to interconnect the Internet as (autonomous system), the most important function of BGP is to control the transmission of Routing and select the best route. Netcom, China Telecom, China Railcom and some large private IDC operators have the as number, the country's major network operators are mostly through BGP protocol and its own as number to achieve multiple-line interconnection. The so-called BGP computer room as an autonomous system (equivalent to an operator's autonomous system), through the BGP protocol to interconnect with other operators.

The BGP room needs to apply for its IP address and as number in the CNNIC (China Internet Information Center) or APNIC (Asia Pacific Network Information Center), and then broadcast the IP address to other network operators via the BGP protocol.

The advantage of the BGP room is that it can easily interconnect with various operators, including the three operators and some small operators, to avoid such problems as a pure unicom IDC communicating with the telecom network. BGP room and small operators can be directly connected to avoid the need to pass through the network of three major operators to interconnect.

In the actual production, there are some so-called "dual-line room", for example, a IDC is access to telecommunications fiber is also connected to the optical fiber, to achieve an IDC and a number of operators connected. Therefore, "dual-line room" and the BGP room has the essential difference.