路由ospf的配置

1、it education & trainingdate: 24 october 2021计算机系 邹瑞源计算机网络互联技术 it education & trainingdate: 24 october 2021 ospf简介 ospf是一种典型的链路状态路由协议。采用ospf的路由器彼此交换并保存整个网络的链路信息，从而掌握全网的拓扑结构，独立计算路由。 ospf作为一种内部网关协议（interior gateway protocol，igp），用于在同一个自治域（as）中的路由器之间发布路由信息。区别于距离矢量协议(rip)，ospf具有支持大型网络、路由收敛快、占用网络资

2、源少等优点，在目前应用的路由协议中占有相当重要的地位。it education & trainingdate: 24 october 2021ospf简介开放的国际标准开放的国际标准shortest path first (spf最短路径优先最短路径优先) 算法算法链路状态路由协议链路状态路由协议it education & trainingdate: 24 october 2021ospf 概述 通过交换hello数据包来创建邻居关系 以传播lsa（ link-state advertisements ）代替路由表更新. 链路（link）：路由器接口 状态（state）：描述

3、接口以及它与邻居路由器的关系 lsas 泛洪到区域中的所有ospf路由器，而不仅仅是直连路由器 收集由ospf路由器生成的所有lsa以创建ospf链路状态数据库. 使用spf算法计算到每个目的地的最短距离，并将其置于路由表中.it education & trainingdate: 24 october 2021ospf术语it education & trainingdate: 24 october 2021shortest path first algorithm 将每台路由器放置在树的根节点，并根据累计开销计算到将每台路由器放置在树的根节点，并根据累计开销计算到达每个目的

4、地的最短路径达每个目的地的最短路径 开销（开销（cost） = 参考带宽（参考带宽（108）/接口带宽接口带宽 (bps)it education & trainingdate: 24 october 2021ospf特点详介特点详介ospfopen shortest path first 使用cost（成本）作为其路由度量值，其默认成本基于介质的传输带宽来度量it education & trainingdate: 24 october 2021ospf特点详介特点详介三大优越性： 1、收敛时间快 2、支持vlsm和cidr 3、网络的扩展性强 对跳数基本没有限制，对于跳数过

5、多的网络可通过层次化的设计，将达的ospf网络化分成小的、易管理的ospf域it education & trainingdate: 24 october 2021ospf 层级示列 区域和自治系统区域和自治系统 尽量减少路由表条目尽量减少路由表条目 使拓扑变化仅影响本区域内部使拓扑变化仅影响本区域内部it education & trainingdate: 24 october 2021ospf数据包类型（ospf packet types）it education & trainingdate: 24 october 2021 ospf 的五种分组类型 类型类型1，

6、问候，问候(hello)分组。分组。类型类型2，数据库描述，数据库描述(database description)分组。分组。类型类型3，链路状态请求，链路状态请求(link state request)分组。分组。类型类型4，链路状态更新，链路状态更新(link state update)分组，分组， 用洪泛法对全网更新链路状态。用洪泛法对全网更新链路状态。类型类型5，链路状态确认，链路状态确认(link state acknowledgment) 分组。分组。 it education & trainingdate: 24 october 2021ospf操作操作 1. 建立邻接关

7、系2. 必要的进行dr选举3. 发现路由4. 选择相应的路由5. 维护路由信息it education & trainingdate: 24 october 2021建立邻接关系建立邻接关系*标记的在邻居路由器上必须匹配标记的在邻居路由器上必须匹配it education & trainingdate: 24 october 2021ospf网络类型network typenetwork typecharacteristicscharacteristicsdr/bdr elected?dr/bdr elected?以太网（以太网（ethernetethernet）yes帧中继（

8、帧中继（frame relayframe relay）yesppp, hdlcppp, hdlcno管理员用子接口配置（管理员用子接口配置（configured by administrator configured by administrator with subinterfaceswith subinterfaces）noframe relayx.25广播broadcast multiaccess非广播nonbroadcast multiaccess点到点point-to-point点到多点point-to-multipointit education & trainingdat

9、e: 24 october 2021点到点链路（point-to-point links）不进行dr选举ospf自动检测这种接口类型it education & trainingdate: 24 october 2021广播型多路访问网络进行dr选举邻居只与dr和dbr形成邻接关系it education & trainingdate: 24 october 2021必要时进行dr选举 dr与bdr的选举取决于路由器的优先级 可通过接口配置模式 ip ospf priority 命令修改该路由器的优先级 如果优先级相同，则比较router id。 router id： 默认值：

10、ospf过程启动时活动接口上的最高ip地址 可以使用环回接口覆盖：环回接口的最高ip地址（次优先） 可以使用router-id命令手动设置（最优先）it education & trainingdate: 24 october 2021选举dr和bdr最高接口优先级的路由器被选成dr最高路由器id的路由器被选举成drdr选举不具有抢占性it education & trainingdate: 24 october 2021建立双向通信建立双向通信it education & trainingdate: 24 october 2021建立双向通信it education

11、& trainingdate: 24 october 2021建立双向通信it education & trainingdate: 24 october 2021建立双向通信it education & trainingdate: 24 october 2021查找网络路由it education & trainingdate: 24 october 2021查找网络路由it education & trainingdate: 24 october 2021增加链路状态条目it education & trainingdate: 24 octob

12、er 2021增加链路状态条目it education & trainingdate: 24 october 2021增加链路状态条目it education & trainingdate: 24 october 2021维护路由信息路由器用路由器用224.0.0.6通知通知dr it education & trainingdate: 24 october 2021维护路由信息dr利用组播地址利用组播地址224.0.0.5通知其它路由器通知其它路由器it education & trainingdate: 24 october 2021维护路由信息it edu

13、cation & trainingdate: 24 october 2021维护路由信息it education & trainingdate: 24 october 2021配置单区域的ospfrouter(config-router)# network address wildcard-mask area area-id 将网络分配到将网络分配到ospf 区域区域router(config)# router ospf process-id 将将 ospf定义为定义为 ip 路由协议路由协议it education & trainingdate: 24 october

14、 2021ospf 配置示列it education & trainingdate: 24 october 2021ospf配置实例it education & trainingdate: 24 october 2021验证ospf 配置router# show ip protocols 检验是否已配置检验是否已配置ospfrouter# show ip route 显示路由器所学习到的所有路由显示路由器所学习到的所有路由router# show ip routecodes: i - igrp derived, r - rip derived, o - ospf derived

15、, c - connected, s - static, e - egp derived, b - bgp derived, e2 - ospf external type 2 route, n1 - ospf nssa external type 1 route, n2 - ospf nssa external type 2 route gateway of last resort is 10.119.254.240 to network 10.140.0.0 o e2 10.110.0.0 160/5 via 10.119.254.6, 0:01:00, ethernet2 e 10.67

16、.10.0 200/128 via 10.119.254.244, 0:02:22, ethernet2 o e2 10.68.132.0 160/5 via 10.119.254.6, 0:00:59, ethernet2 o e2 10.130.0.0 160/5 via 10.119.254.6, 0:00:59, ethernet2 e 10.128.0.0 200/128 via 10.119.254.244, 0:02:22, ethernet2 . . .it education & trainingdate: 24 october 2021router# show ip

17、 ospf验证ospf 配置 显示显示ospf路由器、计时器和统计信息路由器、计时器和统计信息router# show ip ospfrouting process ospf 1 with id 172.16.6.1 start time: 00:38:41.540, time elapsed: 00:00:25.860 supports only single tos(tos0) routes supports opaque lsa supports link-local signaling (lls) supports area transit capability router is n

18、ot originating router-lsas with maximum metric initial spf schedule delay 5000 msecsarea backbone(0) (inactive) number of interfaces in this area is 1 area has no authentication spf algorithm last executed 00:00:07.368 ago spf algorithm executed 1 times.it education & trainingdate: 24 october 20

19、21router# show ip ospf interface验证ospf 配置 显示区域显示区域 id 和邻接信息和邻接信息router# show ip ospf interface ethernet 0 ethernet 0 is up, line protocol is up internet address 192.168.254.202, mask 255.255.255.0, area 0.0.0.0 as 201, router id 192.168.99.1, network type broadcast, cost: 10 transmit delay is 1 sec,

20、 state other, priority 1 designated router id 192.168.254.10, interface address 192.168.254.10 backup designated router id 192.168.254.28, interface addr 192.168.254.28 timer intervals configured, hello 10, dead 60, wait 40, retransmit 5 hello due in 0:00:05 neighbor count is 8, adjacent neighbor co

21、unt is 2 adjacent with neighbor 192.168.254.28 (backup designated router) adjacent with neighbor 192.168.254.10 (designated router) it education & trainingdate: 24 october 2021验证ospf 配置router# show ip ospf neighbor显示每个接口上的显示每个接口上的ospf邻居信息邻居信息router# show ip ospf neighbor id pri state dead time a

22、ddress interface 10.199.199.137 1 full/dr 0:00:31 192.168.80.37 ethernet0 172.16.48.1 1 full/drother 0:00:33 172.16.48.1 fddi0 172.16.48.200 1 full/drother 0:00:33 172.16.48.200 fddi0 10.199.199.137 5 full/dr 0:00:33 172.16.48.189 fddi0 it education & trainingdate: 24 october 2021验证ospf 配置router

23、# show ip ospf neighbor 10.199.199.137 neighbor 10.199.199.137, interface address 192.168.80.37 in the area 0.0.0.0 via interface ethernet0 neighbor priority is 1, state is full options 2 dead timer due in 0:00:32 link state retransmission due in 0:00:04 neighbor 10.199.199.137, interface address 17

24、2.16.48.189 in the area 0.0.0.0 via interface fddi0 neighbor priority is 5, state is full options 2 dead timer due in 0:00:32 link state retransmission due in 0:00:03 router# show ip ospf neighbor detail neighbor 192.168.5.2, interface address 10.225.200.28 in the area 0 via interface gigabitetherne

25、t1/0/0 neighbor priority is 1, state is full, 6 state changes dr is 10.225.200.28 bdr is 10.225.200.30 options is 0 x42 lls options is 0 x1 (lr), last oob-resync 00:03:08 ago dead timer due in 00:00:36 neighbor is up for 00:09:46 index 1/1, retransmission queue length 0, number of retransmission 1 f

26、irst 0 x0(0)/0 x0(0) next 0 x0(0)/0 x0(0) last retransmission scan length is 1, maximum is 1 last retransmission scan time is 0 msec, maximum is 0 msec it education & trainingdate: 24 october 2021ospf 调试命令router# debug ip ospf eventsospf:hello with invalid timers on interface ethernet0hello inte

27、rval received 10 configured 10net mask received 255.255.255.0 configured 255.255.255.0dead interval received 40 configured 30router# debug ip ospf packet ospf: rcv. v:2 t:1 l:48 rid:200.0.0.117 aid:0.0.0.0 chk:6ab2 aut:0 auk: router# debug ip ospf packet ospf: rcv. v:2 t:1 l:48 rid:200.0.0.116 aid:0

28、.0.0.0 chk:0 aut:2 keyid:1 seq:0 x0it education & trainingdate: 24 october 2021实验环境ab192.168.1.64/27192.168.1.32/27192.168.1.104/29it education & trainingdate: 24 october 2021ospf的基本配置router_a#config terminalrouter_a（config）#router_a（config）#router ospf 1 /启动ospf协议，其进程为1 router_a（config-rout

29、er）#network 192.168.1.32 0.0.0.31 area 0router_a（config-router）#network 192.168.1.64 0.0.0.31 area 0it education & trainingdate: 24 october 2021router_b#config terminalrouter_b（config）#router_b（config）#router ospf 1 /启动ospf协议，其进程为1 router_b（config-router）#network 192.168.1.32 0.0.0.31 area 0rout

30、er_b（config-router）#network 192.168.1.104 0.0.0.7 area 0it education & trainingdate: 24 october 2021ospf身份验证 ospf支持以下几种类型的身份验证： -空（无身份验证） -明文（或简单）口令身份验证 -md5身份验证 路由器生成并检查每个ospf数据包。 路由器验证接收到的每个路由更新数据包的来源。 配置“密钥”（口令）：每个参与的邻居都必须配置相同的密钥。it education & trainingdate: 24 october 2021配置ospf身份验证步骤一：设

31、定验证的口令 1、设定明文口令 router（config-if）# ip ospf authentication-key password 分配用于邻居路由器的口令（最长8个字符） 2、设定md5加密的口令 router（config-if）# ip ospf message-digest-key id md5 password 分配用于邻居路由器的口令（md5加密，最长16个字符）it education & trainingdate: 24 october 2021配置ospf身份验证步骤二：启用ospf身份验证并指定验证类型 方法1：在接口上直接指定（12.0版本以上提供） r

32、outer（config-if）# ip ospf authentication message-digest | null 指定接口的身份验证类型 message-digest ：md5加密口令 null ：空口令 方法2：整个ospf 区域指定验证类型 router（config-router）# area area-id authentication message-digest message-digest ：md5加密口令it education & trainingdate: 24 october 2021使用ospf配置负载均衡ospf负载均衡 路径必须为等价路径 默认情

33、况下，最多可在路由表中加入4条等价路径 通过更改配置，最多可以配置16条等价路径 -（config-router）# maximum-paths 可更改链路的开销以确保路径等价进行负载均衡 -（config-if）# ip ospf cost it education & trainingdate: 24 october 2021修改链路成本router#router#config terminalrouter(config)#interface f0/0router(config-if)#ip ospf cost number/number为为1到到65535之间的值之间的值it e

34、ducation & trainingdate: 24 october 2021internet互联网局域网：内部使用ospf接入互联网使用默认路由内部计算机如何使用默认路由？默认路由it education & trainingdate: 24 october 2021默认路由发布到ospf区域 将默认路由发布到ospf区域中，使用以下命令： router（config-router）# default-information originateit education & trainingdate: 24 october 2021课堂作业e0e0s0s0it education & trainingdate: 24 october 2021思考题（questions）1. ospf是一种典型的_路由协议。2. ospf路由协议的管理距离是_。3. ospf路由协议采用_作为度量标准。4. ospf路由器利用_算法，独立地计算出到达任意目的地的路由。5. 默认情况下，快速以太网的开销是_。6. ospf将网络划分为四种类型：_、_、_、_。7. ethernet的hello interval为_秒，dead interval为_秒。8. nbma网络的hello interval_秒，dead interva