Introduction to the Internal Gateway Routing Protocol

In the internal gateway routing protocol, we mainly introduce the enhanced internal gateway routing protocol. For details, refer to the following link. Enhanced inner Gateway Routing Protocol Enhanced Interior Gateway Routing Protocol, which is a network Protocol. Compared with earlier network protocols, it enables vrouters to exchange information more effectively. It is developed by the Internal Gateway Routing Protocol (IGRP) and the routers can interact with each other, regardless of whether it is used by the VPN gateway or IGRP, because the metric used in a protocol is used to select the routing standard) it can be converted to another protocol's metric. Enhance the internal gateway routing protocol, which can be used not only in the Internet protocol, but also in one of the network protocols used by the AppleTalkMac machine) and in the Novell NetWare network.

The router retains a copy of the route table of its neighboring router. If it cannot find a route to its destination from these tables, it asks its neighboring routers for a route and they take turns asking about their neighboring routers until they find a route. When the entry of a route table changes in one of the routers, it will only notify its neighboring routers of the change that some earlier protocols require to send the entire route table ). To ensure that all routers are aware of the status of neighboring routers, Each router regularly sends a "hello" packet. A router that does not receive the "hello" packet within a certain period of time is considered invalid.

Enhance the routing protocol of the Internal Gateway using the diffusion refresh algorithm DUAL) to determine the most effective and minimum cost to reach the destination. The diffusion refresh algorithm finite state machine includes the decision information used by the algorithm and determines the route with the least cost. It considers whether the distance and the path to the destination are non-circular ).

The internal gateway routing protocol is a Cisco proprietary protocol developed in the middle of 1980s. It helps overcome the defects of routing selection information protocols such as a single measurement standard for computing hops. The Internal Gateway Routing Protocol has stable functions, similar to the Internal Gateway Routing Protocol, such as the suppression of timers, horizontal split, and toxicity reversal. The scheduled time is as follows: 270 seconds are invalid, 280 seconds are blocked, and 630 seconds are refreshed. The Internal Gateway Routing Protocol also includes the mechanism that affects route selection and load balancing of non-equivalent values. IGRP/VPN is measured as follows:

◆ Bandwidth

◆ Relay

◆ Reliability

◆ Load

◆ MTU Information Transmission Unit)

The internal gateway routing protocol is an internal gateway protocol. It is a distance vector routing protocol based on the Bellman-Ford algorithm. This algorithm broadcasts route update information every 90 seconds on IP Protocol 9. The internal gateway routing protocol is very suitable for small and medium networks. However, Cisco has enhanced its performance and added support for the VLSM variable-length subnet mask of the VPN.

In early 1990s, Cisco developed an enhanced internal gateway routing protocol to overcome the limitations of the routing information protocol and the internal gateway routing protocol. Cisco said that the Internal Gateway Routing Protocol will be deleted from the IOS Internet Operating System. The enhanced Internal Gateway Routing Protocol is applicable to large networks and supports multiple routing protocols. The enhanced Internal Gateway Routing Protocol consumes less bandwidth because it adopts partial and bundled updates. It is one of the fastest aggregation routing protocols. The features of the Enhanced Internal Gateway Routing Protocol are as follows:

◆ Cisco proprietary protocol.

◆ Suitable for small to large networks.

◆ Setting is very simple. Use an autonomous system number.

◆ Supports multiple layer-3 routing protocol stacks, such as IP, Novell IPX, and Appletalk.

◆ Advanced distance vector routing protocol.

◆ Because of its ability to gradually update and quickly aggregate, it is usually called hybrid.

◆ IGP Internal Gateway Protocol ).

◆ Occasionally launch Multi-broadcast updates at 224.0.0.10.

◆ IP Protocol No. 88.

◆ The internal management distance is 90, and the external management distance is 170.

◆ Bandwidth, relay, reliability, load, and information transmission units are measured.

◆ Supports equal-cost and non-Equal-cost load balancing.

◆ Other stability functions supporting route loops include horizontal split and toxicity reversal.

◆ Use the diffusion update algorithm (DUAL) to select routes without route loops and quickly aggregate them.

◆ Supports VLSM and automatic summary without category ).

◆ Border Summary of automatic classification.

◆ Manually send abstract updates to various interfaces.

◆ If the number of the autonomous system is the same, it will be automatically released using the internal gateway routing protocol.

◆ Policy-based routing.

Enhance the reliability of the Internal Gateway Routing Protocol from the Reliable Transport Protocol (RTP. It not only retains the route table, but also has neighbors and Topology tables. Enhance the Internal Gateway Routing Protocol and retain the alternative routes as the successor route table) and the feasible successor topology table) for quick aggregation. The following are the data packet types used for neighbor communication: hellos Multicast) and acks unidirectional broadcast), update multicast or unidirectional broadcast), query Multicast), and reply to unidirectional broadcast) and request multicast or unidirectional broadcast ). Packets are arranged during transmission and each Protocol has a separate neighbor table and a completely separate process.