What are the classifications of dynamic routing protocols? The dynamic routing protocol generates and maintains the routing table required by the forwarding engine through the exchange of routing information. When the network topology changes, the dynamic routing protocol can automatically update the routing table and is responsible for determining the best path for data transmission.
Classified by path finding algorithm, the dynamic routing protocol differs according to the addressing algorithm, it can be divided into distance vector routing protocols and link state routing protocols.
- The distance vector routing protocol uses the distance vector (Distance-Vector, DV) algorithm, which exchanges the entire routing table between adjacent routers, superimposes the vectors, and finally learns the entire routing table.
- The link state routing protocol uses the link state (Link State, LS) algorithm. The link state is a hierarchical type. The router that implements this algorithm does not simply learn routes from neighboring routers, but divides the routers into areas, collects the link state information of all routers in the area, and generates a network based on the link state information Topological structure, each router calculates the route according to the topology diagram. Link state routing protocols include OSPF, IS-IS, etc.
The network of a large ISP classified by work area may contain thousands of routers, while a small provider usually has only a dozen routers. Each ISP manages its own internal network, which is generally called an administrative domain, and its connection with other ISPs is called an inter-domain connection. Therefore, the Internet can be seen as interconnected by individual domains.
As the network is divided into management domains (AS), according to the scope of application of the protocol, two corresponding routing protocols are produced, namely interior gateway protocol and exterior gateway protocol.
- Interior Gateway Protocol (Interior Gateway Protocol, IGP)
The interior gateway protocol is a routing protocol responsible for routing within a routing domain (a domain that runs the same routing protocol in an administrative domain, called a routing domain). Intra-domain routing protocols include: RIP, OSPF, IS-IS, etc.
- Exterior Gateway Protocol (Exterior Gateway Protocol, EGP)
The Exterior routing protocol is responsible for completing the interaction of routing and reachable information between autonomous systems or between domains, and is mainly used to transfer routing. Inter-domain routing protocols include: EGP, BGP.
Classified by routing type, IP data packets in the Internet are generally point-to-point applications, but there are also point-to-multipoint applications, such as audio/video conferences (multimedia conferences), and real-time information (such as stocks)for data transmission, online games and simulation, we call the routing of these two types of IP data packets as unicast routing and multicast routing, respectively.
The structure of the routing and forwarding table used by unicast routing and multicast routing when transmitting IP data packets is different, and the information in the IP data packets used is also different (not described in detail), which separates two routing protocols , Respectively are unicast routing protocol and multicast routing protocol.
- Unicast routing protocol
Unicast routing protocol is a protocol for generating and maintaining unicast routing table. Unicast routing protocols include RIP, OSPF, IS-IS, IGRP, BGP, etc.
- Multicast routing protocol
Multicast routing protocol is a protocol for generating and maintaining multicast routing table. Multicast routing protocols include DVMRP, PIM-SM, PIM-DM, MOSPF, MBGP, etc.
