Common Internet Router Protocol classification encyclopedia

For the router protocol this term, probably many people have been familiar with, especially the current network development quickly, Internet Router Protocol is also constantly improving, but also appeared a lot of new features. The wide application of information technology in various fields has promoted the rapid development of information exchange network, in which the Internet is the biggest beneficiary. The main node equipment of the

Internet network is the router, which determines the forwarding of the data by routing. The forwarding strategy is called routing (routing), which is also the origin of the router name (router, forwarding). The method of decision forwarding can be artificially specified, but the person for the designated workload is large, and can not take flexible strategy, so the dynamic router protocol came into being, through the transmission, analysis, calculation, select routing, to complete routing discovery, routing, Routing and load sharing functions. The

RIP, OSPF, and BGP protocols

Now run on a large number of router protocols on the Internet that are RIP, OSPF, and BGP. RIP, OSPF is an internal gateway protocol that applies to the operation of a single ISP's unified router protocol, and a network operated by an ISP is called an autonomous system (AS). BGP is a router protocol between autonomous systems and an external gateway protocol.

Rip is the longest-growing router protocol and the simplest router protocol. It is the acronym for routing Information Protocol, which mainly transmits routing information (routing table) to broadcast routes: every 30 seconds, broadcast a routing table, maintain the relationship between neighboring routers, and compute its own routing table based on the routing table received. RIP is simple to run and applies to small networks, where RIP is partly used on the Internet. The

OSPF protocol is an abbreviation for "Open Shortest Path First". "Open" is for some manufacturers at that time "private" router protocol, and it is because of the openness of the Protocol, the OSPF today is a powerful vitality and a wide range of uses. It obtains the network information through the transmission link state (the connection information), maintains a network to have the topological graph, uses the minimum spanning tree algorithm (SPF algorithm) to obtain the route table. OSPF is a relatively complex router protocol.

in general, OSPF and RIP are router protocols within autonomous systems that are suitable for use by a single ISP (autonomous system). Generally speaking, the entire internet is not appropriate to run a single router protocol, because each ISP has its own interests, do not want to provide their own network detailed routing information. In order to ensure the interests of each ISP, the standardization organization developed the router protocol BGP between ISPs.

BGP is the abbreviation for the Boundary Gateway Protocol, which handles routing delivery between each ISP. It is characterized by a rich routing strategy, this is the RIP, OSPF and other protocols can not be done,Because they need global information to compute the routing table. BGP through the ISP boundary of the router plus the affirmative policy, select the filter route, the RIP, OSPF, BGP and other routes sent to each other. A global, extensive internet is an instance of the BGP process of routing between multiple ISPs. The advent of BGP has caused great changes in the Internet, and it has connected many ISPs organically and become a global network. The side effect is the Internet routing explosion, and now the Internet route is probably 60,000, which is the number after the "aggregation". Configuring BGP requires a particular understanding of user needs, network status, and BGP protocols, as well as--the need to be particularly careful that BGP runs at a relatively central position, and that the resulting loss can be huge if it goes wrong!

A new mode of transmission, multicast (multicast), is emerging for a one-to-many multicast application such as weather forecasts, web conferencing, and so on over the Internet network. Multicast is suitable for one to many transmission environment, but also can be applied to many, many to one situation. Multicast forwarding is mainly determined by routers, and routers determine the so-called downstream in two ways: decide whether there is a downstream of the host (user), pass the Multicastclient (IGMP) protocol, decide whether there are indirect users, that is, through the "downstream" router with the team, The router determines whether to forward data to the downstream router through a multicast router Protocol message notification. It can be seen that the application of multicast router protocol in the second way is the key of large scale network multicast forwarding. Multicast router protocol should be able to communicate the information of the crew at least, and can form a globally unified routing topology. The

Intensive mode is suitable for small networks, assuming that there is a special "intensive" team presence throughout the network, using broadcast + pruning work strategies. The default assumption is to forward the data to all downstream, and then remove the interface from the downstream list when it receives a clear pruning message from a downstream stream. In general, the forwarding path should be a "source" as the root, the group members of a tree foliage. Dense-mode router protocols include DVMRP, MOSPF, and PIMDM.