We all know that routers are hardware devices that link two or more networks and can act as gateways between networks. It has the intelligence to read the address of each data packet and then decide how to transmit. This is true for home routers, enterprise routers or industrial routers that are commonly used in our homes
Why do routers use protocols? In fact, routers receive and forward data through routing tables. Forwarding strategies can be manually specified through static or policy routing methods. If the network is small, there will be no problem. If the network is large and only forwarding strategies are manually specified, there will be a huge workload, and it will become very difficult to manage and maintain the routing tables, Therefore, to solve these problems, dynamic routing protocols are essential.
What are the common router protocols? Common routing protocols include RIP, IGRP (Cisco Private Protocol), EIGRP (Cisco Private Protocol), OSPF, IS-IS, BGP, etc.
Main entry: Routing information protocol
RIP (Routing Information Protocol) is one of the longest used protocols. RIP is a distributed distance vector based routing protocol, which was introduced by Xerox in the 1980s and is mainly applicable to small-scale network environments. RIP protocol is mainly used for the transmission of routing information in an AS (autonomous system), sending routing information updates every 30s.
Main entry: open shortest path first
OSPF routing protocol is a link state routing protocol for Internet Protocol (IP) networks. The protocol uses the internal gateway protocol (IGP) of link state routing algorithm to work within a single autonomous system (AS). The OSPFv2 protocol for IPv4 is defined in RFC 2328, and RFC 5340 defines OSPFv3 for IPv6.
Main entry: Intermediate system to intermediate system
IS-IS belongs to the internal gateway routing protocol and is used in the autonomous system. IS-IS is a link state protocol, which is very similar to the OSPF protocol in TCP/IP networks. It uses the shortest path first algorithm for routing calculation.
Main entry: Internal gateway routing protocol
IGRP, the inter gateway routing protocol, is an internal gateway protocol using distance vector algorithm. It provides routing protocols in an autonomous system, a patent protocol developed by Cisco Systems. Its algorithm is similar to that of the Routing Information Protocol (RIP). It manages routes through user configurations, such as latency, bandwidth, reliability, and load equal to each router.
Main entry: Enhanced Internal Gateway Routing Protocol
EIGRP combines the Cisco special protocol of link state and distance vector routing protocol, uses the diffusion correction algorithm (DUAL) to achieve rapid convergence, does not send regular route update information to reduce bandwidth consumption, and supports multiple network layer protocols such as Appletalk, IP, Novell, and NetWare.
Main entry: Border Gateway Protocol
Main entry: Border Gateway Protocol
Border Gateway Protocol (BGP) is a routing protocol for autonomous systems running on TCP. BGP is the only protocol used to handle Internet size networks, and the only protocol that can properly handle multiple connections between unrelated routing domains. BGP is built on the experience of EGP. The main function of BGP system is to exchange network access information with other BGP systems. The network reachable information includes the listed information of autonomous system (AS). This information effectively constructs the topology map of AS interconnection and thus clears the routing loop. At the same time, policy decisions can be implemented at the AS level.