NBMA实验

实验准备：
1、 四台路由器，R2配置成帧中继交换机。

2、 R1，R3，R4运行OSPF。

实验配置：

R1：

interface Loopback0

ip address 1.1.1.1 255.255.255.0

ip ospf network point-to-point 使路由正常。

interface Serial0/0

ip address 134.1.1.1 255.255.255.0

encapsulation frame-relay 封装成帧中继。

ip ospf network non-broadcast 配置成NBMA的网络。

ip ospf priority 255 使R1成为DR。接口悠闲级。

frame-relay map ip 134.1.1.3 103 broadcast 用广播方式发送帧中继信息。静态映射。（注意：对方IP和己方DLCI）

frame-relay map ip 134.1.1.4 104 broadcast

no frame-relay inverse-arp 关闭自动映射。

router ospf 1

log-adjacency-changes

network 1.1.1.0 0.0.0.255 area 0

network 134.1.1.0 0.0.0.255 area 0

neighbor 134.1.1.3 priority 3 在NBMA的网络中，只能使用neighbor来指明邻居还可以指明邻居的优先级。

neighbor 134.1.1.4

SWITCH：

frame-relay switching 配置成帧中继交换机。此命令很重要。

interface Serial0/0

no ip address

encapsulation frame-relay 封装成帧中继

clockrate 128000

frame-relay lmi-type cisco 配置帧中继的类型

frame-relay intf-type dce 配置帧中继为DCE

frame-relay route 103 interface Serial0/1 301 做帧中继映射

frame-relay route 104 interface Serial0/2 401

interface Serial0/1

no ip address

encapsulation frame-relay

clockrate 128000

frame-relay lmi-type cisco

frame-relay intf-type dce

frame-relay route 301 interface Serial0/0 103

interface Serial0/2

no ip address

encapsulation frame-relay

clockrate 128000

frame-relay lmi-type cisco

frame-relay intf-type dce

frame-relay route 401 interface Serial0/0 104

R3：

interface Loopback0

ip address 3.3.3.3 255.255.255.0

ip ospf network point-to-point

interface Serial0/1

ip address 134.1.1.3 255.255.255.0

encapsulation frame-relay

ip ospf network non-broadcast

ip ospf priority 3

frame-relay map ip 134.1.1.1 301 broadcast

frame-relay map ip 134.1.1.4 301 broadcast

no frame-relay inverse-arp

router ospf 1

log-adjacency-changes

network 3.3.3.0 0.0.0.255 area 0

network 134.1.1.0 0.0.0.255 area 0

R4：

interface Loopback0

ip address 4.4.4.4 255.255.255.0

ip ospf network point-to-point

interface Serial0/1

ip address 134.1.1.4 255.255.255.0

encapsulation frame-relay

ip ospf network non-broadcast

ip ospf priority 0

frame-relay map ip 134.1.1.1 401 broadcast

frame-relay map ip 134.1.1.3 401 broadcast

no frame-relay inverse-arp

router ospf 1

log-adjacency-changes

network 4.4.4.0 0.0.0.255 area 0

network 134.1.1.0 0.0.0.255 area 0

实验结果：

R1#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

3.3.3.3 3 FULL/BDR 00:01:31 134.1.1.3 Serial0/0

4.4.4.4 0 FULL/DROTHER 00:01:57 134.1.1.4 Serial0/0

R1#show ip route ospf

3.0.0.0/24 is subnetted, 1 subnets

O 3.3.3.0 [110/782] via 134.1.1.3, 00:11:56, Serial0/0

4.0.0.0/24 is subnetted, 1 subnets

O 4.4.4.0 [110/782] via 134.1.1.4, 00:11:56, Serial0/0

R3：frame-relay map ip 134.1.1.4 301 broadcast

R4：frame-relay map ip 134.1.1.3 401 broadcast

以上两条命令的说明：

如果你加这两条命令，在R3上和R4上都能看见带O的路由，如：

R3#show ip route ospf

1.0.0.0/24 is subnetted, 1 subnets

O 1.1.1.0 [110/782] via 134.1.1.1, 00:00:16, Serial0/1

4.0.0.0/24 is subnetted, 1 subnets

O 4.4.4.0 [110/782] via 134.1.1.4, 00:00:16, Serial0/1

R3#ping 4.4.4.4

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 4.4.4.4, timeout is 2 seconds:

…..

Success rate is 0 percent (0/5)

R4#show ip route ospf

1.0.0.0/24 is subnetted, 1 subnets

O 1.1.1.0 [110/782] via 134.1.1.1, 00:00:35, Serial0/1

3.0.0.0/24 is subnetted, 1 subnets

O 3.3.3.0 [110/782] via 134.1.1.3, 00:00:35, Serial0/1

R4#ping 3.3.3.3

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:

…..

Success rate is 0 percent (0/5)

说明即使有路由，但是没有帧中继映射还是不能够通信。

加上这两条命令后：

R3#show ip route ospf

1.0.0.0/24 is subnetted, 1 subnets

O 1.1.1.0 [110/782] via 134.1.1.1, 00:04:15, Serial0/1

4.0.0.0/24 is subnetted, 1 subnets

O 4.4.4.0 [110/782] via 134.1.1.4, 00:04:15, Serial0/1

R3#ping 4.4.4.4

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 4.4.4.4, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 56/57/60 ms

R4#show ip route ospf

1.0.0.0/24 is subnetted, 1 subnets

O 1.1.1.0 [110/782] via 134.1.1.1, 00:03:57, Serial0/1

3.0.0.0/24 is subnetted, 1 subnets

O 3.3.3.0 [110/782] via 134.1.1.3, 00:03:57, Serial0/1

R4#ping 3.3.3.3

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 56/57/60 ms