EIGRP协议概述
EIGRP是最典型的平衡混合路由选择协议，它融合了距离
矢量和链路状态两种路由选择协议的优点，使用闪速更新
算法，能最快的达到网络收敛（convergence）
EIGRP特点如下：
? 采用不定期更新，即只在路由器改变计量标准或拓扑出
现变化时发送部分更新路由
? 更新条目中包含掩码，支持VLSM，支持不连续子网
? 具有相同的自治系统号的EIGRP和IGRP之间，
可无缝交换路由信息
EIGRP主要功能
? 通过协议相关模块支持IP,IPX,AppleTalk
? 无类
? 支持VLSM和CIDR
? 支持概要和不练许网络
? 有效邻居发现
? 基于可靠传输协议（RTP）的通信
? 基于弥散更新算法（DUAL）的最佳路径的选择
路由发现和维护
三表：
? 邻居关系表：以建立的邻居关系
? 拓扑表：
互联网中每个路由器从每个邻居 接受到的路由通告
? 路由表：当前使用的用于路由判断的路由度量：0带宽1，延迟，负载，可靠性，最大传输单 元
配置 EIGRP
Router(config)#router eigrp {as-number}
启动EIGRP
Router(config-router)#network {network-number
宣告直连主类网络号
用试验验证EIGRP的配置。
试验环境介绍
R1的ip地址为 192.168.1.1 （S0/0） 网络掩码为 255.255.255.0
R2的ip地址为 192.168.1.2 （S0/0） 192.168.2.1 （S0/1）网络掩码为 255.255.255.0
R3的ip地址为 192.168.2.2 （S0/1） 网络掩码为 255.255.255.0
R1的S0/0端口和R2的S0/1端口为DCE端口
AS号为100
试验目的，通过在路由器间配置EIGRP协议，使路由器间能相互通讯，实现全网全通
下面分别是在R1 R2 R3上的配置。(红色字体为配置内容)
R1
Router>en
Router#conf t
Enter configuration commands, .e per line. End with CNTL/Z.
Router(config)#host r1
r1(config)#int s0/0
r1(config-if)#ip addr 192.168.1.1 255.255.255.0
r1(config-if)#clock rate 64000
r1(config-if)#no shut
r1(config-if)#exit
r1(config)#router eigrp 100
r1(config-router)#network 192.168.1.0
R2
Router>en
Router#conf t
Enter configuration commands, .e per line. End with CNTL/Z.
Router(config)#host r2
r2(config)#int s0/0
r2(config-if)#ip addr 192.168.1.2 255.255.255.0
r2(config-if)#no shut
r2(config-if)#exit
r2(config)#int s0/1
r2(config-if)#ip addr 192.168.2.1 255.255.255.0
r2(config-if)#clock rate 64000
r2(config-if)#no shut
r2(config-if)#exit
r2(config)#router eigrp 100
r2(config-router)#network 192.168.1.0
r2(config-router)#network 192.168.2.0
R3
Router>en
Router#conf t
Enter configuration commands, .e per line. End with CNTL/Z.
Router(config)#host r3
r3(config)#int s0/1
r3(config-if)#ip addr 192.168.2.2 255.255.255.0
r3(config-if)#no shut
r3(config-if)#exit
r3(config)#router eigrp 100
r3(config-router)#network 192.168.2.0
如下是在路由器R1上分别ping R2 R3的信息，
试验证明R1 R2 R3已经实现全网全通。
r1#ping 192.168.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 144/445/576 ms
r1#ping 192.168.2.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 364/788/1224 ms
r1#ping 192.168.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 720/1085/1412 ms
如下是在路由器R1 R2 R3上查看路由协议。结果表明，R1 R2 R3之间是通过Eigrp 实现全网全通的
R1
r1#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
EIGRP NSF-aware route hold timer is 240s
Automatic network summarization is in effect
Maximum path: 4
Routing for Networks:
192.168.1.0
Routing Information Sources:
Gateway Distance Last Update
192.168.1.2 90 00:04:24
Distance: internal 90 external 170
R2
r2>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
EIGRP NSF-aware route hold timer is 240s
Automatic network summarization is in effect
Automatic address summarization:
192.168.1.0/24 for Serial0/1
Maximum path: 4
Routing for Networks:
192.168.1.0
192.168.2.0
Routing Information Sources:
Gateway Distance Last Update
192.168.2.2 90 00:00:05
Distance: internal 90 external 170
R3
r3#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
EIGRP NSF-aware route hold timer is 240s
Automatic network summarization is in effect
Maximum path: 4
Routing for Networks:
192.168.2.0
Routing Information Sources:
Gateway Distance Last Update
192.168.2.1 90 00:00:44
Distance: internal 90 external 170
OK，试验成功啦！
下面是一些验证命令:
Show ip eigrp neighbors 用于显示运行eigrp路由协议的邻居关系
Show ip eigrp toplogy 显示eigrp 路由协议的拓扑表
Show ip route eigrp 显示eigrp 路由协议的路由表
Show ip eigrp traffic 显示eigrp协议数据包的通讯状态
