RIP protocol
RIP (Routing Information Protocol, Routing Information Protocol) is an interior gateway protocol (the IGP), is a dynamic routing protocol, routing information is transmitted within an autonomous system (AS) is used. RIP protocol based on the distance vector algorithm (DistanceVectorAlgorithms), the use of "hops" (ie metric) to measure the distance of the route to the destination address. This router agreement concerned only with the world around them, only to exchange information with their neighboring routers, the range is limited to 15 hops (15 degrees), the further away, it does not care anymore. RIP applied to the application layer of the OSI network model five. Management defined from the manufacturers (AD, i.e., priority) are as follows: Priority is defined Huawei 100, priority 120 is defined by Cisco.
RIP protocol uses the distance vector algorithm, it has been less applicable in practical use. By default, RIP uses a very simple metric system: the distance is the number of links leading to the site required for the purpose of passing, ranging from 0 to 16, the value 16 indicates the path of infinite length. RIP RIP process to send and receive packets using UDP port 520. RIP packet sent after every 30s transmitted in the form of a broadcast, in order to prevent a "broadcast storm", the subsequent packets will make a random delay. In RIP, if a route is not in the brush 180s, the corresponding distance is set to infinity, and removes the entry from the routing table. RIP divided into two groups: a request packet and a response packet.
Historical evolution, RIP-1 has been proposed earlier, many of which are defective. In order to improve the lack of RIP-1, proposed an improved RIP-2 in RFC1388, RFC1723 and revised in RFC2453 and in. RIP-2 defines a set of effective refinement, the new RIP-2 subnet supported by the selected support CIDR, multicast support, and provides authentication mechanism.
With the advent of OSPF and IS-IS, and many people believe that RIP is obsolete. But in fact RIP also has its own advantages. For a small network, RIP will cost in terms of bandwidth occupied by small, easy to configure, manage, and implement, and RIP are still a lot of use. However, RIP also has obvious shortcomings, there will be loops that is, when there are multiple networks. In order to solve loops, IETF proposed segmentation method range, the router can not learn it by routing interface to declare the route. Division range solves the problem of routing loop between two routers, but can not prevent three or more routers routing loops. Triggered update is another way to solve the problem of the loop, it requires the router to immediately transmit its routing table when the link changes. This accelerates the aggregation network, but prone to flooding broadcast. In short, to solve the loop problem needs to consume a certain time and bandwidth. When using the RIP, the internal network number of links through which not more than 15, which makes it unsuitable for large networks the RIP.
V1V2 difference
1.RIPv1 is like routing protocols, RIPv2 is a classless routing protocol
2.RIPv1 not support VLSM, RIPv2 supports VLSM.
3.RIPv1 no authentication function, RIPv2 supports authentication and clear text and MD5 have two authentication.
4.RIPv1 no manual tabulation function, RIPv2 can be closed automatically aggregate the premise of manual summary.
5.RIPv1 broadcast updates, RIPv2 multicast updates.
6.RIPv1 unmarked routing function, RIPv2 can play tag (tag) for routing, used to filter and make policy.
update 7.RIPv1 sent can carry up to 25 route entries, RIPv2 can only carry a maximum of 24 routes in the presence of authentication.
8.RIPv1 update packets transmitted there is no next-hop attribute, RIPv2 with a next-hop attribute can be used with the re-routing updates.
Here to do a little experiment, simple use GNS3 take a dynamic simulation software RIP routing.
The following is a simple test topology:
Explain the host IP address of 192.168.10.10 PC1 through three routes above, the data packet transmitted to the IP address of PC2 192.168.40.10.
After the completion of a simple topological structures we first turn on the device and configure them.
设置完成后，尝试用PC1ping一下PC2，现在无法连通。
接下来进入路由1的端口0/0跟0/1端口，给端口配上IP地址并开启端口。
然后进入RIP协议的编辑模式，然后输入version 2开启版本协议2，然后输入no auto-summary关闭协议的汇聚功能。然后声明自己直联的两个网段，这是路由1号的设置，其他两个路由也是同样的设置。
路由2号的设置。
接下就是路由3号的设置了。
然后检查他们有没有学习到路由条目。看来以下结果，三台路由都已经成功的学习到了所有网段的条目，接下来测试PC1能不能跟PC2连通。
这边这个小实验就成功了。
