© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-1 EIGRP 配置 EIGRP 是一种高级的距离矢量型路由选择协议, 但它又依 赖于一些常见于链路状态型路由选择协议的特性。

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-2 本节大纲： 1 ，配置 EIGRP 2 ，路由汇总 3 ， EIGRP Load Balancing 4 ， EIGRP Stub 3 ，在 NBMA 网络中运行 EIGRP

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-3 router eigrp autonomous-system-number Defines EIGRP as the IP routing protocol. All routers in the internetwork that must exchange EIGRP routing updates must have the same autonomous system number. 1, 配置 EIGRP network network-number [wildcard-mask]( 反掩码 ) Identifies attached networks participating in EIGRP. wildcard-mask: An inverse mask used to determine how to read the address. The mask has wildcard bits, where 0 is a match and 1 is “don’t care.” Router(config)# Router(config-router)#

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-4 Configuring EIGRP for IP Network is not configured on router A because it is not directly connected to router A. 反掩码为 :

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-5 r71#sh ip route eigrp 100 D /24 [90/ ] via , 00:10:32, Serial1.1 D /24 [90/ ] via , 00:10:28, Serial1.1 D /24 [90/ ] via , 00:10:34, Serial1.1 D /24 [90/ ] via , 00:10:25, Serial1.1 D /24 [90/ ] via , 00:10:34, Serial1.1 r71# r71#ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 60/62/64 ms r71#sh ip route eigrp 100 D /17 [90/ ] via , 00:00:32, Serial1.1 r71#

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-6 Using the Wildcard Mask in EIGRP 将 排除在外 !

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-7 2,EIGRP 路由汇总： Router eigrp 2446 No auto-summary 大多数情况下, 自动路由归纳是一件好事, 它可以使路 由表尽量保持精简 ; 如有不连续的子网, 自动路由归纳就 必须关闭. 当然, 我们还可手工汇总 eigrp 路由 : Interface s0 Ip summary-address eigrp

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-8 附：路由汇总大全 一， IGRP ： Interface e0 Ip summary-address igrp 二， EIGRP router eigrp 15 no auto-summary Int s0 Ip summary-address eigrp ( 更灵活 ) 三， OSPF ： Router ospf 64 ABR:Area 1 range ASBR:Summary-address

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-9 附：路由汇总大全 四， ISIS Router isis Net c0a.2aa9.00 Summary-address 五， BGP Router bgp 254 No auto-summary Aggregate-address summary-only

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-10 Routing Protocol Comparison Chart

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-11 no auto-summary (config-router)# Turns off auto summarization for the EIGRP process Configuring Route Summarization ip summary-address eigrp [as-number] [address] [mask] (config-if)# Creates a summary address this interface will generate

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-12 Summarizing EIGRP Routes

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-13 r50(config)#interface serial 0 r50(config-if)#ip summary-address ? eigrp Enhanced Interior Gateway Routing Protocol (EIGRP) rip Routing Information Protocol (RIP) r50(config-if)#ip summary-address eigrp ? Autonomous system number r50(config-if)#ip summary-address eigrp 44 ? A.B.C.D IP address r50(config-if)#ip summary-address eigrp ? Administrative distance r50(config-if)#ip summary-address eigrp

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1— ， EIGRP Load Balancing( 负载均衡 ) Routes with a metric equal to the minimum metric are installed in the routing table ( 等开销负 载均衡 ). There can be up to six entries in the routing table for the same destination: –The number of entries is configurable. –The default is four. （ maximum-path 1/6 ） –Set the routing table to one entry to disable load balancing.

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-15 EIGRP Unequal-Cost Load Balancing EIGRP offers unequal-cost load balancing.( 也支 持度量值不同的多条路径之间负载均衡 ) Variance allows the router to include routes with a metric smaller than the multiplier times the minimum metric route to that destination –Multiplier is the number specified by the variance command

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-16 Variance Example Router E chooses router C to get to network Z because FD = 20. With a variance of 2, router E chooses router B to get to network Z ( = 30) < [2 x (FD) = 40]. Router D is not used to get to network Z (45 > 40).

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-17 Variance Example r50(config)#router eigrp 44 r50(config-router)#variance ? Metric variance multiplier r50(config-router)#variance 4 r50(config-router)#

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-18 EIGRP 默认路由 1 ：在路由器上配置默认路由（注意！ 只能是本机出口），然后使用 命令 network 公布到 eigrp 里，或者使用重分布将静态公布进 来。 2 ：使用命令 r1(config)#ip default-network x.x.x.x 来创建默认（这 个网段必须是主类的，公布到出口路由器的 eigrp 里的）, 在网络里扩 散。（ rip 的不用公布，这个例外） 3 ：使用 EIGRP 汇总创建默认路由 在出口路由器指向内部的接口上做汇总，指向 (config-if)#ip summary-address eigrp

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-19 EIGRP 被动接口 r1(config-router)#passive-interface x r1(config-router)#passive-interface default r1(config-router)#no passive-interface x 被动接口可以用来防止建立邻居关系，减少数据发送。

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1— ， Configuring EIGRP Stub eigrp stub [receive only|connected|static|summary] 中央－分支网络拓扑常使用末节路由选择；可以极大的提高网 络的稳定性；可以进一步简化中央－分支网络的配置和维护工 作。 只应该在末节路由器上使用 EIGRP 末节路由选择特性，它与核 心网络相连，且不会用来中转数据流；末节路由器的 EIGRP 邻 居全部是中央路由器。 EIGRP 末节特性是在 IOS12.0(7) T 中首次引入的。 Receive only: 禁止它向其他路由器发送任何类型的路由, 只接受路由。 Connected: 允许它发送直连路由，缺省被启用。 Static: 允许它发送静态路由。 Summary: 允许 EIGRP 末节选择特性发送汇总路由，缺省被启用。 Router(config-router)#

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-21 Configuring EIGRP Stub If stub connected is configured: B will advertise /24 to A. B will not advertise /23( 汇总 路由 ), /23( 汇总路由 ), or /24( 静态路由 ). If stub summary is configured: B will advertise /23 to A. B will not advertise /24, /24, or /24.

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-22 Configuring EIGRP Stub If stub static is configured: B will advertise /24 to A. B will not advertise /24, /23, or /24. If stub receive-only is configured: B will not advertise anything to A, so A needs to have a static route to the networks behind B to reach them.

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-23 Configuring EIGRP Stub Rack50_Term_Serv(config)#router eigrp 44 Rack50_Term_Serv(config-rout)#eigrp stub ? connected Do advertise connected routes receive-only Set IP-EIGRP as receive only neighbor static Do advertise static routes summary Do advertise summary routes Rack50_Term_Serv(config-rout)#eigrp stub Rack50_Term_Serv(config-rout)#

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-24 EIGRP Query Process Stuck in Active The router has to get all the replies from the neighbors with an outstanding query before the router calculates the successor information. If any neighbor fails to reply to the query within 3 minutes by default, the route is SIA, and the router resets the neighbor relationship with the neighbor that fails to reply.

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-25 Active Process Enhancement

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1— ，在广域网中实现 EIGRP ： EIGRP supports different WAN links: –Point-to-point links –NBMA Multipoint links Point-to-point links EIGRP configurations can address bandwidth utilization over an interface –EIGRP uses 50% of bandwidth by default –Interface s0 –Bandwidth 20/224/768 –Ip bandwidth-percent eigrp 1 200

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1— ，在广域网中实现 EIGRP ：

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1— ，在广域网中实现 EIGRP ： Configure lowest CIR VC as point-to-point, specify BW = CIR Configure higher CIR VCs as multipoint, combine CIRs

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-29 6, 核验 EIGRP 的运行 Show ip eigrp neighbors Show ip eigrp interfaces Show ip eigrp topology show ip eigrp topology all-links Show ip eigrp traffic Debug eigrp packets Debug ip eigrp

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-30 Verifying EIGRP: show ip route RouterA# show ip route Codes: C - connected, S - static, I - IGRP, R - RIP, D - EIGRP, EX - EIGRP external, O - OSPF, (text omitted) * - candidate default, Gateway of last resort is not set /24 is subnetted, 1 subnets D [90/ ] via , 06:04:01, Serial0/ /24 is subnetted, 4 subnets D [90/ ] via , 05:54:47, Serial0/0 D [90/ ] via , 06:19:41, Serial0/0 C is directly connected, Serial0/0 C is directly connected, Ethernet0/0

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-31 Verifying EIGRP: show ip protocols RouterA# show ip protocols Routing Protocol is "eigrp 100" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Default networks flagged in outgoing updates Default networks accepted from incoming updates EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0 EIGRP maximum hopcount 100 EIGRP maximum metric variance 1 Redistributing: eigrp 100 Automatic network summarization is not in effect Maximum path: 4 Routing for Networks: / Routing Information Sources: Gateway Distance Last Update :50:13 Distance: internal 90 external 170

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-32 Verifying EIGRP: show ip eigrp topology RouterA# show ip eigrp topology IP-EIGRP Topology Table for AS(100)/ID( ) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P /24, 1 successors, FD is via ( /28160), Serial0/0 P /24, 1 successors, FD is via ( /384000), Serial0/0 P /24, 1 successors, FD is via Connected, Serial0/0 P /24, 1 successors, FD is 2190 via Connected, Ethernet0/0 P /24, 1 successors, FD is via ( /384000), Serial0/0

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-33 小结 : 1, 是一种 CISCO 私有的路由协议 ; 2,EIGRP 与 IGRP 可以无缝集成 ; 3,EIGRP 有三张表 ; 4,EIGRP 有 HELLO 包, 确认包, 更新包, 查询包和 响应数据包, 来与邻居交换路由信息. 5,EIGRP 缺省情况下, 在有类网络边界自动归纳 路由信息, 也可以手动汇总优化路由。

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-34 LAB 1, 获取 EIGRP 包的建立过程。 2, 配置 EIGRP 归纳 ; 3, 在 NBMA 的环境中配置 EIGRP;

© 2003, Cisco Systems, Inc. All rights reserved. CSPFA 3.1—4-35 Verifying EIGRP Connectivity: Stable Network RouterA# debug eigrp packets Normal Hello Processing 01:38:29: EIGRP: Sending HELLO on Serial0/0 01:38:29: AS 100, Flags 0x0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 01:38:31: EIGRP: Received HELLO on Serial0/0 nbr :38:31: AS 100, Flags 0x0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0 Received EIGRP Update 01:38:33: EIGRP: Received UPDATE on Serial0/0 nbr :38:33: AS 100, Flags 0x0, Seq 23/37 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0 01:38:33: EIGRP: Enqueueing ACK on Serial0/0 nbr :38:33: Ack seq 23 iidbQ un/rely 0/0 peerQ un/rely 1/0 01:38:33: EIGRP: Sending ACK on Serial0/0 nbr :38:33: AS 100, Flags 0x0, Seq 0/23 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 1/0 01:38:33: EIGRP: Enqueueing UPDATE on Serial0/0 iidbQ un/rely 0/1 serno :38:33: EIGRP: Sending UPDATE on Serial0/0 nbr :38:33: AS 100, Flags 0x0, Seq 38/23 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno :38:33: EIGRP: Received ACK on Serial0/0 nbr :38:33: AS 100, Flags 0x0, Seq 0/38 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1