我们在接口配置过程中，帧中继的DLCI号和IP映射时也没有配置broadcast 参数，这类问题该如何解决?下面小编给你带来的内容回答以上疑问。
EIGRP路由协议的配置拓扑图
EIGRP路由协议的配置实例解析
R1(config)#router eigrp 100
R1(config-router)#no auto-summary //关闭自动汇总
R1(config-router)#net //宣告路由条目
R1(config-router)#end
R2(config)#router eigrp 100
R2(config-router)#no auto-summary
R2(config-router)#net
R2(config-router)#net //宣告路由条目
R2(config-router)#end
R3(config)#router eigrp 100
R3(config-router)#no auto-summary
R3(config-router)#net
R3(config-router)#net
R3(config-router)#end
检查：
R1#show ip eigrp neighbors //查看eigrp 邻居表，发现并没有邻居
IP-EIGRP neighbors for process 100
R1#show ip eigrp topology //查看EIGRP 拓扑表，并没有学习到任何的路由
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 , 1 successors, FD is 2169856
via Connected, Serial0/0
因为帧中继默认为NBMA 模式，也就是非广播的多路访问模式，它会阻止广播数据和组播数据，我们在接口配置过程中，帧中继的DLCI 号和IP 映射时也没有配置broadcast 参数，而EIGRP 路由协议通过组播地址 来发送相应的路由信息(比如hello、update 等数据包)，所以R1 并没有发现任何的邻居路由器。
为了能让EIGRP的路由信息通过帧中继传播，在没有配置broadcast 参数的情况下，我们可以通过单播的形式来发送EIGRP 数据包，我们对以上的配置进行改进：
R1(config)#router eigrp 100
R1(config-router)#neighbor serial 0/0 //手工指定邻居，实现单播方式
R1(config-router)#neighbor serial 0/0
R1(config-router)#end
R2(config)#router eigrp 100
R2(config-router)#neighbor serial 0/0 //手工指定邻居，实现单播方式
R2(config-router)#end
R3(config)#router eigrp 100
R3(config-router)#neighbor serial 0/0 //手工指定邻居，实现单播方式
R3(config-router)#end
验证：
*Mar 1 00:29:18.955: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor (Serial0/0) is up: new adjacency
*Mar 1 00:29:19.115: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor (Serial0/0) is up: new adjacency
R1#show ip eigrp neighbors
IP-EIGRP neighbors for process 100
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
1 Se0/0 156 00:01:19 99 594 0 3
0 Se0/0 154 00:01:19 137 822 0 3
R2#
*Mar 1 00:29:18.979: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor (Serial0/0) is up: new adjacency
R2#
R2#show ip eigrp neighbor
IP-EIGRP neighbors for process 100
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
0 Se0/0 138 00:02:31 171 1026 0 7
R1#show ip route eigrp 100 //查看路由表，可以看到R1 能够学习到R2 和R3 相应的网络
is subnetted, 4 subnets
D [90/2297856] via , 00:03:45, Serial0/0
D [90/2297856] via , 00:03:45, Serial0/0
D [90/2297856] via , 00:03:45, Serial0/0
D [90/2297856] via , 00:03:45, Serial0/0
is subnetted, 4 subnets
D [90/2297856] via , 00:03:45, Serial0/0
D [90/2297856] via , 00:03:45, Serial0/0
D [90/2297856] via , 00:03:45, Serial0/0
D [90/2297856] via , 00:03:45, Serial0/0
R1#ping //验证是否可以访问R2 的网络
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 = 20/56/104 ms
R1#ping //验证是否可以访问R3 的网络
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 = 8/52/124 ms
查看R2 的路由表：
R2#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
is subnetted, 4 subnets
C is directly connected, Loopback3
C is directly connected, Loopback2
C is directly connected, Loopback1
C is directly connected, Loopback0
C is directly connected, Serial0/0
发现R2 并没有学习到R3 的 网络， R1 通过S0/0 接口学习到R3 宣告的网络，因为R1 s0/0 接口的水平分割机制导致R1 不会再由这个接口S0/0 发布出去，所以R2无法学习到R3 宣告的网络，同理，R3 也无法学习到R2 宣告的网络。
对帧中继配置进行修正，使用broadcast 参数：
R1(config)#router eigrp 100
R1(config-router)#no neighbor s0/0 //取消手工指定邻居
*Mar 1 00:42:29.807: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor (Serial0/0) is down:
R1(config-router)#no neighbor s0/0
*Mar 1 00:42:32.623: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor (Serial0/0) is down:
R1(config-router)#exit
R1(config)#int s0/0
R1(config-if)#no fram map ip 102 //取消之前不带broadcast 参数的静态映射
R1(config-if)#no fram map ip 103
R1(config-if)#frame map ip 102 broadcast
R1(config-if)#frame map ip 103 broadcast
R1(config-if)#end
R2(config)#router eigrp 100
R2(config-router)#no neighbor Serial0/0
R2(config-router)#int s0/0
R2(config-if)#no frame-relay map ip 201
R2(config-if)# frame-relay map ip 201 broadcast
R3(config)#router eigrp 100
R3(config-router)#no neighbor Serial0/0
R3(config-router)#int s0/0
R3(config-if)#no
*Mar 1 00:47:58.943: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor (Serial0/0) is up: new adjacency
R3(config-if)#no frame-relay map ip 301
R3(config-if)#frame-relay map ip 301 broadcast
R3(config-if)#end
验证结果：
可以看到添加了broadcast 后，帧中继可以正常的.传递组播数据了，R1 就可以和R2 和R3 建立邻居关系并正常学习到路由。
R1#show ip eigrp neighbors
IP-EIGRP neighbors for process 100
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
1 Se0/0 178 00:00:03 906 5000 0 7
0 Se0/0 178 00:01:57 1040 5000 0 6
R1#show ip route eigrp 100
is subnetted, 4 subnets
D [90/2297856] via , 00:00:53, Serial0/0
D [90/2297856] via , 00:00:53, Serial0/0
D [90/2297856] via , 00:00:53, Serial0/0
D [90/2297856] via , 00:00:53, Serial0/0
is subnetted, 4 subnets
D [90/2297856] via , 00:02:46, Serial0/0
D [90/2297856] via , 00:02:46, Serial0/0
D [90/2297856] via , 00:02:46, Serial0/0
D [90/2297856] via , 00:02:46, Serial0/0
查看R3 的路由表，发现R3 并没有学习到R2 的网络，这是因为R1 默认情况下接口有水平。
R3#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
is subnetted, 4 subnets
C is directly connected, Loopback0
C is directly connected, Loopback1
C is directly connected, Loopback2
C is directly connected, Loopback3
C is directly connected, Serial0/0
将R1 接口的水平分割关闭：
R1(config)#interface serial 0/0
R1(config-if)#no ip split-horizon eigrp 100
R1(config-if)#end
当R1 的水平分割关闭后，EIGRP 进程会出现相应提示：
*Mar 1 00:52:25.055: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor (Serial0/0) is resync: split horizon changed
*Mar 1 00:52:25.055: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor (Serial0/0) is resync: split horizon changed
查看R1 接口S0/0 的情况：
R1#show ip int s0/0 | include Split
Split horizon is disabled
查看R2 的路由表：
R2#show ip route eigrp 100
is subnetted, 4 subnets
D [90/2809856] via , 00:08:03, Serial0/0
D [90/2809856] via , 00:08:03, Serial0/0
D [90/2809856] via , 00:08:03, Serial0/0
D [90/2809856] via , 00:08:03, Serial0/0
虽然R2 路由表中有 网络，但R2 并没有ping 通，这是什么原因?
因为R3 的串行口帧中继配置时，只做了IP 和DLCI 号的对应，没有做IP 192。168.1.2 和DLCI 号的映射，所以R2 ping 时，采用的源地址为，通过路由表发现目的地址 具有符合的条目，转发接口为，于是由R1 转发到R3，R3 在回包过程时，源地址为，而目标地址为，但它不知道这个地址怎么转发于是就丢弃。
R3(config)#int s0/0
R3(config-if)#frame-relay map ip 301 broadcast
R2(config-if)#end
R2(config)#int s0/0
R2(config-if)#frame-relay map ip 201 broadcast
R2(config-if)#end
验证结果：
R2#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 = 44/88/160 ms
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