1、1目录：1.RIP基础部分1）有类路由协议、无类路由协议2）RIP的信息类型3）在网络边界的自动汇总2.RIP Timers RIP的几个时间3.解决RIP中路由回环问题的机制4.RIP的基本配置5.RIP的版本控制:默认情况运行v16.V1与V2的区别7.运行RIP版本1的接口的收发原则8.关于水平分割（Split horizon）9.RIP的自动手工汇总10.RIP的单播更新:(Unicast-Update)/被动接口11.RIP的触发更新12.RIP authentication/RIP 认证13.Offset-list偏置列表,实现RIP路由的控制14.RIP传递默认路由的5种方法1.
2、RIP基础部分1）Classful Routing/有类路由协议IGRP /RIP V11.在发送路由更新信息时,不携带子网掩码,无法描述路由条目的路由长度2.在主类的网络边界上,自动发生路由汇总汇总到主类网络的默认的路由长度(自动汇总是无法关闭的)(不支持VLSM,只能汇总为A/B/C类).3.由于上述原因,有类路由协议会产生“不连续子网“的路由通达性问题.2）Classless Routing/无类路由协议RIP V2 的automatic summary1.不会对收到的明细路由进行汇总2.对自己直连的路由进行汇总后,再通告出去.3.把收到的明细路由放进路由表中,但会对明细路由进行汇总后再
3、通告出去!EIGRP的automatic summary1.不会对收到的明细路由进行汇总,2.对自己直连的路由进行汇总后,再通告出去3.把收到的明细路由放进路由表中,并且把收到的明细路由通告出去!2RIPv2/EIGRP/OSPF/IS-IS/BGPv41.在发送路由更新信息时,已经携带子网掩码.2.支持VLSM,路由的手工/自动汇总,(可以关闭自动汇总)3.在部分先进的路由协议中,支持CIDR(超网)备注：ip classless(在IOS为12.0以后的版本中，默认启动无类路由。)3）RIP的信息类型RIP通过UDP520号端口操作，RIP信息是被封装在UDP的segment中的。通常情况
4、下，RIP有两种信息类型：1、request(请求更新包)：用于向相邻路由器发送一个更新的请求信息2、update（更新回应包）：用于回应request信息4）在网络边界的自动汇总DV协议默认会执行自动汇总,(RIP/IGRP/EIGRP)LS协议默认不执行自动汇总.(OSPF/ISIS)2.RIP Timers RIP的几个时间实验拓扑（以下实验操作均使用本拓扑）：R1(s1/1)-192.168.12.0/24-(s1/1)R2(s1/3)-192.168.23.0/24-(S1/3)R3| | |Lo1 Lo2 Lo3Update timer（更新时间） :1.RIP在启动后，每隔30S
5、（default）从所有RIP Interface 上向外发送update2.这个update 包含了路由器中除了被split horizon（水平分割）抑制的完整的路由表，3.update周期发送的时间间隔默认为(update timer)25.5秒到30秒之间（一个随机值）异步更新；RIP_JITTER是Cisco IOS中专有的一个随机变量，它缩短到一般更新时间的15%（即4.5s） 。因此，在CISCO中的实际更新时间是上25.530秒之间4.RIP V1，update的目标地址为255.255.255.255；RIP V2的为224.0.0.9实验说明：基本配置：r1:interfa
6、ce Loopback0ip address 1.1.1.1 255.255.255.0interface Serial1/13ip address 192.168.12.1 255.255.255.0router ripnetwork 1.0.0.0network 192.168.12.0r2:interface Serial1/1ip address 192.168.12.2 255.255.255.0interface Serial1/3ip address 192.168.23.2 255.255.255.0router ripnetwork 192.168.12.0network 1
7、92.168.23.0r3:interface Serial1/3ip address 192.168.23.3 255.255.255.0router ripnetwork 192.168.23.0路由器R1：默认版本1的update情况*Mar 1 00:21:18.655: RIP: sending v1 update to 255.255.255.255 via Serial1/1 (192.168.12.1)*Mar 1 00:21:18.655: RIP: build update entries - suppressing null update*Mar 1 00:21:25.3
8、63: RIP: received v1 update from 192.168.12.2 on Serial1/1*Mar 1 00:21:25.367: 192.168.23.0 in 1 hopsr1#sh ip route C 192.168.12.0/24 is directly connected, Serial1/1R 192.168.23.0/24 120/1 via 192.168.12.2, 00:00:26, Serial1/1*Mar 1 00:21:52.107: RIP: received v1 update from 192.168.12.2 on Serial1
9、/1*Mar 1 00:21:52.111: 192.168.23.0 in 1 hopssh ip route配置为版本2，关闭auto-summary后R2的update情况*Mar 1 00:06:36.999: RIP: sending v2 update to 224.0.0.9 via Serial1/1 (192.168.12.2)*Mar 1 00:06:36.999: RIP: build update entries*Mar 1 00:06:37.003: 192.168.23.0/24 via 0.0.0.0, metric 1, tag 0*Mar 1 00:06:37
10、.003: RIP: sending v2 update to 224.0.0.9 via Serial1/3 (192.168.23.2)*Mar 1 00:06:37.007: RIP: build update entries*Mar 1 00:06:37.007: 192.168.12.0/24 via 0.0.0.0, metric 1, tag 0*Mar 1 00:07:05.411: RIP: sending v2 update to 224.0.0.9 via Serial1/1 (192.168.12.2)*Mar 1 00:07:05.411: RIP: build up
11、date entries*Mar 1 00:07:05.415: 192.168.23.0/24 via 0.0.0.0, metric 1, tag 0*Mar 1 00:07:05.415: RIP: sending v2 update to 224.0.0.9 via Serial1/3 (192.168.23.2)*Mar 1 00:07:05.419: RIP: build update entries4*Mar 1 00:07:05.419: 192.168.12.0/24 via 0.0.0.0, metric 1, tag 0Invalid timer（无效时间）：1.当有条目
12、加入到路由表中时，该条目的invalid timer就会初始化为180S；2.如果路由器在invalid timer内没有收到该条目的更新信息，那么它在超过180S后将会被标记为不可达，即16跳；3. 它的典型周期范围是36个update周期，无效时间在IOS中缺省是180秒Holddown timer（保持时间）1.180S，如果新收到的路由条目比原有的条目的metric值更大，那么原有的条目会进入一个长为180s的holddown状态；2. 在抑制计时器的时间内该条目标记为possible down，直到计时器超时，路由器才可以接受有关此路由的更新信息原理：该计时器的原理是引用一个怀疑量，
13、不管是真的还是假的路由消息，路由器先认为是假消息来避免路由环路。如果在抑制计时器超时后还接受到该消息，那么这时路由器就认为该消息时真的。RIP中认为假的消息总是真不了，不长久Flush timer（刷新时间） :240S。但RFC1058中规定的是300S。如果超出240S，那么路由被标记为不可达，并从路由表中移除实验说明：r1#sh ip protocols Routing Protocol is “rip“Sending updates every 30 seconds, next due in 9 secondsInvalid after 180 seconds, hold down 1
14、80, flushed after 240Outgoing update filter list for all interfaces is not setIncoming update filter list for all interfaces is not setRedistributing: ripDefault version control: send version 1, receive any versionInterface Send Recv Triggered RIP Key-chainSerial1/1 1 1 2 Loopback0 1 1 2 Automatic n
15、etwork summarization is in effectMaximum path: 4Routing for Networks:1.0.0.0192.168.12.0Routing Information Sources:Gateway Distance Last Update192.168.12.2 120 00:00:28Distance: (default is 120)5通过开启 debug 观察路由表的变化情况：r1#debug ip routing r1#debug ip rip在 R1 上，做访问列表，不接收来自 R2 的 rip 数据包：r1(config)#acce
16、ss-list 111 deny udp any any eq ripr1(config)#access-list 111 permit ip any anyr1(config-if)#ip access-group 111 inr1#sh ip route C 192.168.12.0/24 is directly connected, Serial1/11.0.0.0/24 is subnetted, 1 subnetsC 1.1.1.0 is directly connected, Loopback0R 2.0.0.0/8 120/1 via 192.168.12.2, 00:03:13
17、, Serial1/1R 3.0.0.0/8 120/2 via 192.168.12.2, 00:03:13, Serial1/1R 192.168.23.0/24 120/1 via 192.168.12.2, 00:03:13, Serial1/1180S 后来自 R2 路由条目，被宣告无效，hop=16 跳 （即 invail 计时器走完）*Mar 1 00:30:40.183: RT: delete route to 2.0.0.0 via 192.168.12.2, rip metric 120/1*Mar 1 00:30:40.183: RT: no routes to 2.0.
18、0.0, entering holddown*Mar 1 00:30:40.183: RT: delete route to 3.0.0.0 via 192.168.12.2, rip metric 120/2*Mar 1 00:30:40.183: RT: no routes to 3.0.0.0, entering holddown*Mar 1 00:30:40.183: RT: delete route to 192.168.23.0 via 192.168.12.2, rip metric 120/1*Mar 1 00:30:40.183: RT: no routes to 192.1
19、68.23.0, entering holddown*Mar 1 00:30:40.183: RIP: sending v1 update to 255.255.255.255 via Serial1/1 (192.168.12.1)*Mar 1 00:30:40.183: RIP: build update entries*Mar 1 00:30:40.183: network 1.0.0.0 metric 1 *Mar 1 00:30:40.183: network 2.0.0.0 metric 16*Mar 1 00:30:40.183: network 3.0.0.0 metric 1
20、6*Mar 1 00:30:40.183: network 192.168.23.0 metric 16*Mar 1 00:30:40.183: RIP: sending v1 update to 255.255.255.255 via Loopback0 (1.1.1.1)*Mar 1 00:30:40.183: RIP: build update entries*Mar 1 00:30:40.183: network 2.0.0.0 metric 16*Mar 1 00:30:40.183: network 3.0.0.0 metric 16*Mar 1 00:30:40.183: net
21、work 192.168.12.0 metric 1*Mar 1 00:30:40.183: network 192.168.23.0 metric 16*Mar 1 00:30:42.183: RIP: sending v1 flash update to 255.255.255.255 via Serial1/1 (192.168.12.1)*Mar 1 00:30:42.183: RIP: build flash update entries*Mar 1 00:30:42.187: network 2.0.0.0 metric 16*Mar 1 00:30:42.187: network
22、 3.0.0.0 metric 16*Mar 1 00:30:42.187: network 192.168.23.0 metric 16*Mar 1 00:30:42.191: RIP: sending v1 flash update to 255.255.255.255 via Loopback0 (1.1.1.1)*Mar 1 00:30:42.191: RIP: build flash update entries*Mar 1 00:30:42.195: network 2.0.0.0 metric 16*Mar 1 00:30:42.195: network 3.0.0.0 metr
23、ic 16*Mar 1 00:30:42.199: network 192.168.23.0 metric 166Holddown 计时器开始，进入 possible down 状态r1#sh ip routeC 192.168.12.0/24 is directly connected, Serial1/11.0.0.0/24 is subnetted, 1 subnetsC 1.1.1.0 is directly connected, Loopback0R 2.0.0.0/8 is possibly down, routing via 192.168.12.2, Serial1/1R 3.
24、0.0.0/8 is possibly down, routing via 192.168.12.2, Serial1/1R 192.168.23.0/24 is possibly down, routing via 192.168.12.2, Serial1/1R2的debug输出信息，如下:*Mar 1 00:30:02.051: RIP: received v1 update from 192.168.12.1 on Serial1/1*Mar 1 00:30:02.055: 1.0.0.0 in 1 hops*Mar 1 00:30:18.687: RIP: received v1 u
25、pdate from 192.168.23.3 on Serial1/3*Mar 1 00:30:18.691: 3.0.0.0 in 1 hops*Mar 1 00:30:23.527: RIP: sending v1 update to 255.255.255.255 via Serial1/1 (192.168.12.2)*Mar 1 00:30:23.531: RIP: build update entries*Mar 1 00:30:23.531: network 2.0.0.0 metric 1*Mar 1 00:30:23.531: network 3.0.0.0 metric
26、2*Mar 1 00:30:23.535: network 192.168.23.0 metric 1*Mar 1 00:30:23.535: RIP: sending v1 update to 255.255.255.255 via Serial1/3 (192.168.23.2)*Mar 1 00:30:23.539: RIP: build update entries*Mar 1 00:30:23.539: network 1.0.0.0 metric 2*Mar 1 00:30:23.539: network 2.0.0.0 metric 1*Mar 1 00:30:23.539: n
27、etwork 192.168.12.0 metric 1*Mar 1 00:30:23.539: RIP: sending v1 update to 255.255.255.255 via Loopback0 (2.2.2.2)*Mar 1 00:30:23.539: RIP: build update entries*Mar 1 00:30:23.539: network 1.0.0.0 metric 2*Mar 1 00:30:23.539: network 3.0.0.0 metric 2*Mar 1 00:30:23.539: network 192.168.12.0 metric 1
28、*Mar 1 00:30:23.539: network 192.168.23.0 metric 1*Mar 1 00:30:27.727: RIP: received v1 update from 192.168.12.1 on Serial1/1*Mar 1 00:30:27.731: 1.0.0.0 in 1 hops*Mar 1 00:30:27.731: 2.0.0.0 in 16 hops (inaccessible)*Mar 1 00:30:27.731: 3.0.0.0 in 16 hops (inaccessible)*Mar 1 00:30:27.735: 192.168.
29、23.0 in 16 hops (inaccessible)*Mar 1 00:30:29.791: RIP: received v1 update from 192.168.12.1 on Serial1/1*Mar 1 00:30:29.795: 2.0.0.0 in 16 hops (inaccessible)*Mar 1 00:30:29.795: 3.0.0.0 in 16 hops (inaccessible)*Mar 1 00:30:29.799: 192.168.23.0 in 16 hops (inaccessible)*Mar 1 00:30:46.851: RIP: re
30、ceived v1 update from 192.168.23.3 on Serial1/3*Mar 1 00:30:46.855: 3.0.0.0 in 1 hopsR1中的Flush计时器到期后，删除不可达的路由：【00:30:40.183-00:31:36.611 ；共计56.5左右，Invalid timer 后flush计时器到期】7*Mar 1 00:31:36.611: RT: delete network route to 2.0.0.0*Mar 1 00:31:36.611: RT: NET-RED 2.0.0.0/8*Mar 1 00:31:36.615: RT: NET
31、-RED queued, Queue size 1*Mar 1 00:31:36.615: RT: delete network route to 3.0.0.0*Mar 1 00:31:36.619: RT: NET-RED 3.0.0.0/8*Mar 1 00:31:36.619: RT: NET-RED queued, Queue size 2*Mar 1 00:31:36.623: RT: delete network route to 192.168.23.0*Mar 1 00:31:36.623: RT: NET-RED 192.168.23.0/24*Mar 1 00:31:36
32、.623: RT: NET-RED queued, Queue size 3*Mar 1 00:31:36.627: RIP: sending v1 update to 255.255.255.255 via Serial1/1 (192.168.12.1)*Mar 1 00:31:36.627: RIP: build update entries*Mar 1 00:31:36.631: network 1.0.0.0 metric 1*Mar 1 00:31:36.631: RIP: sending v1 update to 255.255.255.255 via Loopback0 (1.
33、1.1.1)*Mar 1 00:31:36.635: RIP: build update entries*Mar 1 00:31:36.635: network 192.168.12.0 metric 1r1#sh ip route C 192.168.12.0/24 is directly connected, Serial1/11.0.0.0/24 is subnetted, 1 subnetsC 1.1.1.0 is directly connected, Loopback0Sleep Timer:（触发更新计时器）1. 单位毫秒! , 其他计时器单位都是秒；2. RIP使用带毒性逆转(
34、poison reverse)的水平分割(split horizon)和触发更新。触发更新只要在有路由的度量值发生改变时就会产生，而且触发更新不会引起接收路由器重置它们的更新计时器；因为如果这么做，网络拓扑的改变会造成触发更新“风暴”；3. 还需使用另一个计时器，当一个触发更新传播时，这个计时器被随机的设置为1-5s之间的数值；在这个计时器超时前不能发送并发的触发更新。注意：1.在rip的database里面invalid timer时间180秒到了,就进入holddown 180秒，Invalid timer 和 Flush timer 同时开启的；备注：1. 在 holddown time
35、r 开始的时候就开始对外发路由毒化的路由，即hop=16，收到这个路由的设备毒性反转,再发送hop=16 回来(打破水平分割原则 ) ；holddown 的存在理由就是为了使得全网的毒化路由接收一致,防止路由环路2.计时器总结8参考文档http:/ rip r1(config-router)#timers basic ?Interval between updatesr1(config-router)#timers basic 5 ?Invalidr1(config-router)#timers basic 5 10 ?Holddownr1(config-router)#timers basi
36、c 5 10 15 ?Flushr1(config-router)#timers basic 5 10 15 20r1#sh ip protocols Routing Protocol is “rip“Sending updates every 5 seconds, next due in 3 secondsInvalid after 10 seconds, hold down 15, flushed after 20Outgoing update filter list for all interfaces is not setIncoming update filter list for
37、all interfaces is not setRedistributing: rip r1(config)#int s1/1r1(config-if)#ip accessr1(config-if)#ip access-group 111 in无效计时器10s过后，进入holddown计时器；r1#sh ip route C 192.168.12.0/24 is directly connected, Serial1/191.0.0.0/24 is subnetted, 1 subnetsC 1.1.1.0 is directly connected, Loopback0R 2.0.0.0/
38、8 120/1 via 192.168.12.2, 00:00:10, Serial1/1R 3.0.0.0/8 120/2 via 192.168.12.2, 00:00:10, Serial1/1R 192.168.23.0/24 120/1 via 192.168.12.2, 00:00:10, Serial1/1r1#*Mar 1 03:02:13.255: RT: delete route to 2.0.0.0 via 192.168.12.2, rip metric 120/1*Mar 1 03:02:13.255: RT: no routes to 2.0.0.0, enteri
39、ng holddown*Mar 1 03:02:13.259: RT: delete route to 3.0.0.0 via 192.168.12.2, rip metric 120/2*Mar 1 03:02:13.263: RT: no routes to 3.0.0.0, entering holddown*Mar 1 03:02:13.263: RT: delete route to 192.168.23.0 via 192.168.12.2, rip metric 120/1*Mar 1 03:02:13.267: RT: no routes to 192.168.23.0, en
40、tering holddown*Mar 1 03:02:13.271: RIP: sending v1 update to 255.255.255.255 via Serial1/1 (192.168.12.1)*Mar 1 03:02:13.271: RIP: build update entries*Mar 1 03:02:13.271: network 1.0.0.0 metric 1*Mar 1 03:02:13.275: network 2.0.0.0 metric 16*Mar 1 03:02:13.275: network 3.0.0.0 metric 16*Mar 1 03:0
41、2:13.279: network 192.168.23.0 metric 16*Mar 1 03:02:13.279: RIP: sending v1 update to 255.255.255.255 via Loopback0 (1.1.1.1)*Mar 1 03:02:13.283: RIP: build update entries*Mar 1 03:02:13.283: network 2.0.0.0 metric 16*Mar 1 03:02:13.283: network 3.0.0.0 metric 16*Mar 1 03:02:13.287: network 192.168
42、.12.0 metric 1*Mar 1 03:02:13.287: network 192.168.23.0 metric 16同时路由表中显示从R2收的到的路由条目possibly downr1#sh ip route C 192.168.12.0/24 is directly connected, Serial1/11.0.0.0/24 is subnetted, 1 subnetsC 1.1.1.0 is directly connected, Loopback0R 2.0.0.0/8 is possibly down, routing via 192.168.12.2, Serial
43、1/1R 3.0.0.0/8 is possibly down, routing via 192.168.12.2, Serial1/1R 192.168.23.0/24 is possibly down, routing via 192.168.12.2, Serial1/1r1将从R2收到的路由条目进行毒化后，传播到其邻居R2*Mar 1 03:02:15.259: RIP: sending v1 flash update to 255.255.255.255 via Serial1/1 (192.168.12.1)*Mar 1 03:02:15.259: RIP: build flash
44、 update entries*Mar 1 03:02:15.263: network 2.0.0.0 metric 16*Mar 1 03:02:15.263: network 3.0.0.0 metric 16*Mar 1 03:02:15.263: network 192.168.23.0 metric 16*Mar 1 03:02:15.263: RIP: sending v1 flash update to 255.255.255.255 via Loopback0 (1.1.1.1)*Mar 1 03:02:15.263: RIP: build flash update entri
45、es*Mar 1 03:02:15.263: network 2.0.0.0 metric 16*Mar 1 03:02:15.263: network 3.0.0.0 metric 1610*Mar 1 03:02:15.263: network 192.168.23.0 metric 16r1#*Mar 1 03:02:17.759: RIP: sending v1 update to 255.255.255.255 via Serial1/1 (192.168.12.1)*Mar 1 03:02:17.763: RIP: build update entries*Mar 1 03:02:
46、17.763: network 1.0.0.0 metric 1*Mar 1 03:02:17.763: network 2.0.0.0 metric 16*Mar 1 03:02:17.767: network 3.0.0.0 metric 16*Mar 1 03:02:17.767: network 192.168.23.0 metric 16*Mar 1 03:02:17.771: RIP: sending v1 update to 255.255.255.255 via Loopback0 (1.1.1.1)*Mar 1 03:02:17.771: RIP: build update entries*Mar 1 03:02:17.771: network 2.0.0.0 metric 16*Mar 1 03:02:17.775: network 3.0.0.0 metric 16*Mar 1 03:02:17.775: network 192.168.12.0 metric 1*Mar 1 03:02:17.779: network 192.168.23.0 me
