Analysis: Principle of RIP Routing Protocol

This time, we will mainly explain the differences between the two versions of the RIP routing protocol. Compare their message methods and other related content. If you have any questions, refer to "start and run the RIP routing protocol". Here we will briefly review its startup and running, then, we will analyze and compare some of its features and versions. The entire process of RIP startup and running can be described as follows:

When a router initiates RIP, it sends a request packet to the adjacent router in the form of broadcast or multicast. After the RIP of the adjacent router receives the request packet, it responds to the request, the response packet containing the local route table information ｡

After the router receives the response packet, it modifies the local route table and sends the trigger modification packet to the adjacent router to broadcast the route modification information, the router sends a message that triggers the modification to its adjacent routers. After a series of broadcasts that trigger the modification, Each router can obtain and maintain the latest route information ｡

At the same time, RIP broadcasts the local route table to the adjacent router every 30 seconds. After the neighboring router receives the packet, it maintains the local route, selects an optimal route, and broadcasts the modification information to the adjacent network, in this way, the updated route can be globally valid. At the same time, the RIP routing protocol uses the timeout mechanism to process the timeout of outdated routes to ensure the real-time and effective routing ｡

RIP-1 and RIP-2

RIP has two versions: RIP-1 and RIP-2. You can specify the version of the RIP packet processed by the interface ｡

The RIP-1 message transmission mode is the broadcast mode. RIP-2 has two message transmission modes, namely the broadcast mode and the multicast mode, by default, packets are sent in multicast mode. In RIP-2, the multicast address is 224.0.0.9 ｡

The advantage of multicast packet sending is that hosts that do not run RIP in the same network can avoid receiving RIP broadcast packets, sending packets in the multicast mode can also prevent the host running RIP-1 from incorrectly receiving and processing routes with subnet mask in RIP-2. When the interface is running the RIP-2 broadcast mode, you can also receive RIP-1 packets ｡

RIP is a widely used protocol. It is simple, reliable, and easy to configure. However, due to its slow convergence speed, it is only applicable to small and medium homogeneous networks, because it allows a maximum of 15 sites, any destination of more than 15 sites is marked as inaccessible, and RIP broadcasts route information every 30 seconds, RIP is widely used by most IP router manufacturers, it is widely used in most local networks and regional networks with simple structures and strong continuity. For more complex environments and large networks, RIP is generally not used ｡

Advantages and disadvantages of RIP Routing Protocol

The advantage of the RIP Protocol is that it is easy to configure and is very suitable for small-scale networks ｡

The following are the disadvantages of the RIP Protocol:

A large number of broadcasts. RIP broadcasts a complete route table to all neighbors every 30 seconds, which occupies valuable bandwidth resources and is particularly problematic on the slow WAN network link ｡

There is no concept of cost. RIP does not have the concept of network latency and link cost. When RIP is used, the routing/forwarding decisions are only based on jumpers. In this way, it is easy to choose the best route. For example, A link has a high bandwidth, but the number of hops is large, so it cannot be selected ｡

The supported network scale is limited. Because the RIP route protocol supports a maximum of 16 hops, when the number of hops exceeds this threshold, the network cannot be reached, RIP can only be applied to a small number of networks ｡