網(wǎng)絡(luò)設(shè)備安裝與調(diào)試chp25路由優(yōu)化課件

1、路由優(yōu)化 Route Optimization 教學(xué)目標(biāo)（ Objectives ）1. 被動(dòng)接口（Passive Interface）2.分布列表（ Distribute List ）3.前綴列表（ Prefix List）4.偏移列表（Offset List）第一節(jié) 被動(dòng)接口和分布列表控制路由更新（Controlling Routing Updates）Passive interfaceStatic routesDefault routeRoute mapsDistribute listsPrefix lists被動(dòng)接口（Passive Interfaces）對(duì)于特定的協(xié)議，被動(dòng)接口阻止發(fā)

2、送或者接收路由更新Passive interfaces prevent routing updates from being sent and/or received for a specified protocol. RIP可以接收更新，但是不能發(fā)送更新RIP interfaces listen but will not send updates. OSPF和EIGRP不接受也不發(fā)送更新，因而不能形成鄰居關(guān)系OSPF and EIGRP interfaces do not listen for or send updates and therefore no neighbor adjacen

3、cies can be established.passive-interface default Command大的企業(yè)可能配置多個(gè)被動(dòng)接口，在一些網(wǎng)絡(luò)中，可能要使用200多次passive-interface命令。Large enterprise may need to set multiple interfaces as passive.In some networks, this could mean coding 200 or more passive-interface statements. passive-interface default命令把參與相應(yīng)路由協(xié)議的所有接口配置為

4、被動(dòng)接口。The passive-interface default command sets all interfaces as passive by default.需要參與路由更新的接口通過(guò)命令passive-interface default 激活。Interfaces on which adjacencies updates are desired can be set as active with the passive-interface default command.使用passive-interface命令（Using the passive-interface Comma

5、nd）使用分布列表（Using Distribute Lists）分布列表允許ACL應(yīng)用到路由更新中，達(dá)到過(guò)濾的目的Distribute list allows an ACL to be applied to routing updates for filtering purposes.過(guò)濾入向更新（Filter Incoming Routing Updates）Router(config-router)#distribute-list access-list-number | name route-map map-tag in interface-type interface-numberP

6、arameterDescriptionaccess-list-number | nameSpecifies the standard access list number or name.map-tag(Optional) Specifies the name of the route map that defines which networks are to be installed in the routing table and which are to be filtered from the routing table. This argument is supported by

7、OSPFonly.inApplies the access list to incoming routing erface-type interface-number(Optional) Specifies the interface type and number from which updates are filtered.過(guò)濾出向更新（Filter Outgoing Routing Updates）Router(config-router)#distribute-list access-list-number | name out interface-name |

8、 routing-process routing-process parameter ParameterDescriptionaccess-list-number | nameSpecifies the standard access list number or name.outApplies the access list to outgoing routing erface-name(Optional) Specifies the name of the interface out of which updates are filtered. routing-pro

9、cess(Optional) Specifies the name of the routing process, or the keyword static or connected, that is being redistributed and from which updates are filtered.routing-process parameter(Optional) Specifies a routing process parameter, such as the AS number of the routing process.distribute-list out Or

10、 inFilter outgoing routing updatesR1(config-router)# distribute-list 1 outFilter incoming routing updatesR1R1R1(config-router)# distribute-list 2 in使用接口過(guò)濾，隱藏了網(wǎng)絡(luò)Hides network using interface filtering用分布列表過(guò)濾路由更新（Filtering Routing Updates Using Distribute List）Case Study 1：配置被動(dòng)接口和分布列表

11、1.R1發(fā)送EIGRP更新時(shí)，過(guò)濾172.16.X.0路由,其中X為奇數(shù)的路由條目過(guò)濾2.在R2上把EIGRP重分布到OSPF時(shí)，包含172.16.X.0，其中X能被4整除和路由3.在R3上，只希望收到和兩條路由條目第二節(jié) 前綴列表使用前綴列表（Using Prefix Lists）在很多路由過(guò)濾命令中，ACL被前綴列表替代。Prefix lists can be used as an alternative to access lists in many route filtering commands.前綴列表特征（Prefix

12、list characteristics include）:對(duì)于大的列表，裝載和查詢(xún)效率比ACL顯著提升A significant performance improvement over ACLs in loading and route lookup of large lists. 支持增量修改（Support for incremental modifications.）在指定掩碼長(zhǎng)度范圍方面具有更大的靈活性Greater flexibility in specifying subnet mask ranges.配置前綴列表（Configure a Prefix List）Router(

13、config)#ip prefix-list list-name | list-number seq seq-value deny | permit network/length ge ge-value le le-valueParameterDescriptionlist-nameThe name of the prefix list that will be created (it is case sensitive).list-numberThe number of the prefix list that will be created.seq seq-valueDefault seq

14、uence numbers are in increments of 5 (5, 10, 15, and so on).deny | permitThe action taken when a match is work/lengthThe prefix to be matched and the length of the prefix. ge ge-valueThe range is assumed to be from ge-value to 32 if only the ge attribute is specified.le le-valueThe range is assumed

15、to be from length to le-value if only the le attribute is specified.配置前綴列表（Configure a Prefix List）全局模式下，使用no ip prefix-list 命令刪除前綴列表Use the no ip prefix-list list-name global configuration command to delete a prefix list.全局命令ip prefix-list list-name description text 可以增加或者刪除前綴列表描述The ip prefix-list

16、 list-name description text global configuration command can be used to add or delete a text description for a prefix list.提示（Tip）:為了達(dá)到最佳性能，最常用到的陳述應(yīng)該使用較低的序號(hào)。For best performance, the most frequently processed prefix list statements should be configured with the lowest sequence numbers. 前綴列表匹配規(guī)則（Pref

17、ix List Matching rules）精確匹配范圍匹配沒(méi)有l(wèi)e或ge匹配（Prefix List Matching without le or ge）類(lèi)似沒(méi)有通配符掩碼的IP ACL有l(wèi)e或ge匹配（Prefix List Matching with le or ge）前綴列表匹配實(shí)例（Example:Prefix List Matching）ip prefix-list test1 seq 5 permit /0 ge 32 匹配所有主機(jī)路由ip prefix-list test2 seq 10 permit /0 le 32 匹配所有路由ip prefi

18、x-list test4 seq 20 permit /1 ge 8 le 8 匹配A類(lèi)地址ip prefix-list test5 seq 25 permit /2 ge 16 le 16 匹配B類(lèi)地址ip prefix-list test6 seq 30 permit /3 ge 24 le 24 匹配C類(lèi)地址ip prefix-list test7 seq 35 permit /16 le 20ip prefix-list test8 seq 40 permit /16 ge 20Case St

19、udy 2：配置前綴列表/24.1.2s0/0s0/0R1R2Lo0:/24Lo1:/27Lo2:3/28Lo3:5/29Lo4:7/30Lo0:/24.2.3s0/1R3/24s0/1area0area1網(wǎng)絡(luò)運(yùn)行OSPF路由協(xié)議，在R1上重分布直連路由，對(duì)主類(lèi)地址/16網(wǎng)絡(luò)的子網(wǎng)路由進(jìn)行控制，使得：1.直連路由掩碼長(zhǎng)度為24-28的，重分布時(shí)設(shè)置路由類(lèi)型為1,種子度量值為1002.直連路由掩碼長(zhǎng)度大于29的，重

20、分布時(shí)設(shè)置路由類(lèi)型為2,種子度量值為200，路由Tag為2003.重分布其他直連路由時(shí)不做控制。Case Study 2：配置前綴列表R1(config)#ip prefix-list CONN1 seq 5 permit /16 ge 24 le 28R1(config)#ip prefix-list CONN2 seq 5 permit /16 ge 29R1(config)#route-map CONN permit 10R1(config-route-map)#match ip address prefix-list CONN1R1(config

21、-route-map)#set metric 100R1(config-route-map)#set metric-type type-1R1(config)#route-map CONN permit 20R1(config-route-map)#match ip address prefix-list CONN2R1(config-route-map)#set metric 200R1(config-route-map)#set tag 200R1(config)#route-map CONN permit 30R1(config)#router ospf 1R1(config-route

22、r)#redistribute connected subnets route-map CONN第三節(jié) 偏移列表用偏移列表控制路徑（Path Control Using Offset Lists）偏移列表用于出站或者入站方向增加EIGRP或者RIP路由條目的度量值。 An offset list is the mechanism for increasing incoming and outgoing metrics to routes learned via EIGRP or RIP.使用命令offset-list創(chuàng)建偏移列表。To create an offset-list, use th

23、e offset-list router configuration command.只適用于距離向量路由協(xié)議(Distance Vector Routing Protocol only)定義偏移列表（Defining an Offset-List）Router(config-router)#offset-list access-list-number | access-list-name in | out offset interface-type interface-numberParameterDescriptionaccess-list-number | access-list-name Standard access list number or name to be applied. Access list number 0 indicates all access lists. in Applies the access list to incoming metrics. outApplies the access list to outgoing metrics. offset Positive offset to be applied to metrics. If the offset is 0, no action is takenin