帧中继上的OSPF.docx

帧中继是典型的NBMA（NonBroadcast Multiple Access）网络，其拓扑结构通常有两种：Full Mesh(全互联)和Hub-and-Spoke（中心分支）Hub-and-Spoke 结构具有节约费用、简化配置等优点，在实际网络工程中有着广泛的应用。实验1: 帧中继环境下NBMA 模式1.实验目的通过本实验可以掌握：（1）帧中继静态映射及broadcast 参数的含义（2）NBMA 模式下的DR 选举（3）手工配置OSPF 邻居（4）NBMA 模式下OSPF 的配置和调试2.拓扑结构3.实验配置R0 三层交换机模拟帧中继交换机配置frame-relay switching /把该路由器当成帧中继交换机interface Serial1/1 no ip address encapsulation frame-relay serial restart-delay 0 clock rate 128000 /该接口为DCE，要配置时钟 no frame-relay inverse-arp frame-relay lmi-type cisco frame-relay intf-type dce frame-relay route 102 interface Serial1/2 201 frame-relay route 103 interface Serial1/3 301 /“encapsulation frame-relay ietf ”命令用来配置口封装成帧中继，如果不加ietf 参数，帧类型为cisco；如果加ietf 参数，则帧类型为ietf。interface Serial1/2 no ip address encapsulation frame-relay serial restart-delay 0 clock rate 128000 no frame-relay inverse-arp frame-relay lmi-type cisco frame-relay intf-type dce frame-relay route 201 interface Serial1/1 102interface Serial1/3 no ip address encapsulation frame-relay serial restart-delay 0 clock rate 128000 frame-relay lmi-type cisco frame-relay intf-type dce frame-relay route 301 interface Serial1/1 103R1interface Loopback0 ip address 1.1.1.1 255.255.255.0 ip ospf network point-to-point!interface Serial1/1 ip address 123.1.1.1 255.255.255.0 encapsulation frame-relay serial restart-delay 0frame-relay map ip 123.1.1.3 103 broadcast /帧中继静态映射 frame-relay map ip 123.1.1.2 102 broadcast no frame-relay inverse-arp /关闭帧中继动态ARP解析ip ospf network non-broadcast（默认） frame-relay lmi-type cisco!router ospf 1 log-adjacency-changes network 1.1.1.0 0.0.0.255 area 0network 123.1.1.0 0.0.0.255 area 0 neighbor 123.1.1.3 neighbor 123.1.1.2!R2interface Loopback0 ip address 2.2.2.2 255.255.255.0 ip ospf network point-to-point!interface Serial1/2 ip address 123.1.1.2 255.255.255.0 encapsulation frame-relay ip ospf priority 0 /配置spoke端OSPF接口优先级为0ip ospf network non-broadcast（默认） serial restart-delay 0frame-relay map ip 123.1.1.3 201 broadcast frame-relay map ip 123.1.1.1 201 broadcast frame-relay map ip 123.1.1.2 201 no frame-relay inverse-arp frame-relay lmi-type cisco!router ospf 1 log-adjacency-changes network 2.2.2.0 0.0.0.255 area 0 network 123.1.1.0 0.0.0.255 area 0R3 interface Loopback0 ip address 3.3.3.3 255.255.255.0 ip ospf network point-to-point!interface Serial1/3 ip address 123.1.1.3 255.255.255.0 encapsulation frame-relay ip ospf priority 0ip ospf network non-broadcast（默认） serial restart-delay 0 frame-relay map ip 123.1.1.3 301 frame-relay map ip 123.1.1.1 301 broadcast frame-relay map ip 123.1.1.2 301 broadcast no frame-relay inverse-arp!router ospf 1 log-adjacency-changes network 3.3.3.0 0.0.0.255 area 0 network 123.1.1.0 0.0.0.255 area 04.实验调试R3#sh ip ospf interface s1/3Serial1/3 is up, line protocol is up Internet Address 123.1.1.3/24, Area 0 Process ID 1, Router ID 3.3.3.3, Network Type NON_BROADCAST, Cost: 64 Transmit Delay is 1 sec, State DROTHER, Priority 0 Designated Router (ID) 1.1.1.1, Interface address 123.1.1.1 No backup designated router on this network Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5 oob-resync timeout 120 Hello due in 00:00:20 Supports Link-local Signaling (LLS) Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 2 Last flood scan time is 4 msec, maximum is 4 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 1.1.1.1 (Designated Router) Suppress hello for 0 neighbor(s)R1#show ip route ospf 2.0.0.0/24 is subnetted, 1 subnetsO 2.2.2.0 110/65 via 123.1.1.2, 00:00:25, Serial1/1 3.0.0.0/24 is subnetted, 1 subnetsO 3.3.3.0 110/65 via 123.1.1.3, 00:00:25, Serial1/1R1#ping 123.1.1.1 Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 123.1.1.1, timeout is 2 seconds:. /没有配置frame-relay map ip 123.1.1.1 102，不能ping通自己。Success rate is 0 percent (0/5)R1#ping 2.2.2.2Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:!Success rate is 100 percent (5/5), round-trip min/avg/max = 60/91/128 msR1#ping 3.3.3.3Type 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 = 60/80/120 msR2#show ip route 1.0.0.0/24 is subnetted, 1 subnetsO 1.1.1.0 110/65 via 123.1.1.1, 00:05:04, Serial1/2 2.0.0.0/24 is subnetted, 1 subnetsC 2.2.2.0 is directly connected, Loopback0 3.0.0.0/24 is subnetted, 1 subnetsO 3.3.3.0 110/65 via 123.1.1.3, 00:05:04, Serial1/2 123.0.0.0/24 is subnetted, 1 subnetsC 123.1.1.0 is directly connected, Serial1/2R2#traceroute 3.3.3.3Type escape sequence to abort.Tracing the route to 3.3.3.3 1 123.1.1.1 136 msec 80 msec 56 msec 2 123.1.1.3 144 msec * 144 msec从以上输出表明，到达网络“3.3.3.0/24”的路由条目的下一跳地址为“134.1.1.3”，而不是“134.1.1.1”，所以，在R2 的s1/2的接口上必须有到134.1.1.3 的映射“frame-relay map ip 134.1.1.3 201 broadcast”。【技术要点】（1）在帧中继网络上，OSPF 接口缺省的网络类型为NON_BROADCAST。在这种模式下，OSPF 不会在帧中继接口上发送Hello 包，因此无法建立最基本的邻接关系。可以手工使用“neighbor”命令来指定邻居，这时Hello 包以单播形式传送；（2）NBMA 属于多路访问网络，所以要进行DR 选举。由于Hello 包只能传1 跳，所以在Hub-and-Spoke 结构中，必须控制处于“Hub”端的路由器为DR,最保险的办法就是将“Spoke”端接口优先级配置为0，使之不参与DR 选举，“Hub”端的路由器自然就成为DR。否则，可能会导致路由学习不正常。实验2：帧中继环境下BMA 模式1.实验目的（1）帧中继静态映射及broadcast 参数的含义（2）BMA 模式下的DR 选举（3）BMA 模式下OSPF 的配置和调试2.拓扑结构拓扑如实验1图。3.实验配置只需要将R1、R2、R3的模式修改一下即可，例如：R1(config-if)# ip ospf network broadcastinterface Loopback0 ip address 1.1.1.1 255.255.255.0 ip ospf network point-to-point!interface Serial1/1 ip address 123.1.1.1 255.255.255.0 encapsulation frame-relay ip ospf network broadcast /在接口更改ospf网络模式 serial restart-delay 0 clock rate 128000 frame-relay map ip 123.1.1.3 103 broadcast frame-relay map ip 123.1.1.2 102 broadcast no frame-relay inverse-arp frame-relay lmi-type cisco!router ospf 1 log-adjacency-changes network 1.1.1.0 0.0.0.255 area 0 network 123.1.1.0 0.0.0.255 area 0其他设备如上更改 不再详细配置4.实验调试R1#sh ip ospf int s1/1Serial1/1 is up, line protocol is up Internet Address 123.1.1.1/24, Area 0 Process ID 1, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 64/网络类型为BROADCAST Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 1.1.1.1, Interface address 123.1.1.1 No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:00 Supports Link-local Signaling (LLS) Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 2 Last flood scan time is 0 msec, maximum is 4 msec Neighbor Count is 2, Adjacent neighbor count is 2 Adjacent with neighbor 123.1.1.2 Adjacent with neighbor 123.1.1.3 Suppress hello for 0 neighbor(s)R1#show ip route ospf 2.0.0.0/24 is subnetted, 1 subnetsO 2.2.2.0 110/65 via 123.1.1.2, 00:07:17, Serial1/1 3.0.0.0/24 is subnetted, 1 subnetsO 3.3.3.0 110/65 via 123.1.1.3, 00:07:17, Serial1/1【技术要点】（1）在Hub-and-Spoke 结构中，BMA 也要控制DR 选举，确保处于“Hub”端的路由器为DR，实施方法和实验1 一样；（2）BMA 模式下，邻居关系自动通过Hello 包建立和维持。实验3：帧中继环境下点到点（子接口）模式点到点模式(point-to-point)注意要使用frame-relay interface-dlci命令。也不需要手动指定邻居1.实验目的（1）帧中继子接口下静态映射（2）点到点模式的特征（2）点到点模式下OSPF 的配置和调试2.拓扑结构实验1图。3.实验配置R1interface Loopback0 ip address 1.1.1.1 255.255.255.0 ip ospf network point-to-point!interface Serial1/1 no ip address encapsulation frame-relay serial restart-delay 0 no frame-relay inverse-arp!interface Serial1/1.1 point-to-point ip address 123.1.1.1 255.255.255.0 frame-relay interface-dlci 102 !interface Serial1/1.2 point-to-point ip address 123.1.2.1 255.255.255.0 frame-relay interface-dlci 103 !router ospf 1 router-id 1.1.1.1 log-adjacency-changes network 1.1.1.0 0.0.0.255 area 0 network 123.1.1.0 0.0.0.255 area 0 network 123.1.2.0 0.0.0.255 area 0R2interface Loopback0 ip address 2.2.2.2 255.255.255.0 ip ospf network point-to-point!interface Serial1/2 no ip address encapsulation frame-relay serial restart-delay 0 no frame-relay inverse-arp!interface Serial1/2.1 point-to-point ip address 123.1.1.2 255.255.255.0 frame-relay interface-dlci 201 !router ospf 1 router-id 2.2.2.2 log-adjacency-changes network 2.2.2.0 0.0.0.255 area 0 network 123.1.1.0 0.0.0.255 area 0R3 interface Loopback0 ip address 3.3.3.3 255.255.255.0 ip ospf network point-to-point!interface Serial1/3 no ip address encapsulation frame-relay serial restart-delay 0 no frame-relay inverse-arp!interface Serial1/3.1 point-to-point ip address 123.1.2.2 255.255.255.0 frame-relay interface-dlci 301 !router ospf 1 router-id 3.3.3.3 log-adjacency-changes network 0.0.0.0 255.255.255.255 area 04.实验调试R1#sh ip ospf int s1/1.1Serial1/1.1 is up, line protocol is up Internet Address 123.1.1.1/24, Area 0 Process ID 1, Router ID 1.1.1.1, Network Type POINT_TO_POINT, Cost: 64/点到点模式下，Hello周期为10秒 Transmit Delay is 1 sec, State POINT_TO_POINT, Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:08 Supports Link-local Signaling (LLS) Index 2/2, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 4 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 2.2.2.2 Suppress hello for 0 neighbor(s)R1#sh ip ospf neighbor detail Neighbor 3.3.3.3, interface address 123.1.2.2 In the area 0 via interface Serial1/1.2 Neighbor priority is 0, State is FULL, 6 state changes DR is 0.0.0.0 BDR is 0.0.0.0 Options is 0x52 LLS Options is 0x1 (LR) Dead timer due in 00:00:38 Neighbor is up for 00:49:51 Index 1/1, retransmission queue length 0, number of retransmission 1 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 1, maximum is 1 Last retransmission scan time is 4 msec, maximum is 4 msec Neighbor 2.2.2.2, interface address 123.1.1.2 In the area 0 via interface Serial1/1.1 Neighbor priority is 0, State is FULL, 6 state changes DR is 0.0.0.0 BDR is 0.0.0.0 Options is 0x52 LLS Options is 0x1 (LR) Dead timer due in 00:00:38 Neighbor is up for 00:49:11 Index 2/2, retransmission queue length 0, number of retransmission 0 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 0, maximum is 0Last retransmission scan time is 0 msec, maximum is 0 msec【技术要点】1. 点到点模式的DR和BDR是“0.0.0.0”；2. 点到点模式下，每个子接口需要配置不同的网络；3. 点到点模式下，Hello周期为10秒。进入子接口时选point to point,就不能使用frame-relay map命令了,只能用frame-relayinterface-dlci做映射,选multipoint时候2者都可以用点到点子接口就一条PVC所以只需用frame-relay interface-dlci来分配一个dlci号就行(而且是必须的)多点子接口有多个PVC所以用frame-relay map来做映射，区别不同的PVC，因为路由器在启用子接口时inverse-arp不起作用的4. 点到多点广播模式(point-to-multipoint)1.实验目的（1）帧中继子接口下静态映射（2）点到多点模式的特征（3）点到多点模式下OSPF 的配置和调试2.拓扑结构实验1拓扑图3.实验配置R1interface Loopback0 ip address 1.1.1.1 255.255.255.0 ip ospf network point-to-point!interface Serial1/1 no ip address encapsulation frame-relay serial restart-delay 0 no frame-relay inverse-arp!interface Serial1/1.1 multipoint ip address 123.1.1.1 255.255.255.0 ip ospf network point-to-multipoint frame-relay map ip 123.1.1.3 103 broadcast frame-relay map ip 123.1.1.2 102 broadcast no frame-relay inverse-arp!router ospf 1 router-id 1.1.1.1 log-adjacency-changes network 1.1.1.0 0.0.0.255 area 0 network 123.1.1.0 0.0.0.255 area 0R2interface Loopback0 ip address 2.2.2.2 255.255.255.0 ip ospf network point-to-point!interface Serial1/2 ip address 123.1.1.2 255.255.255.0 encapsulation frame-relay ip ospf network point-to-multipoint serial restart-delay 0 frame-relay map ip 123.1.1.1 201 broadcast no frame-relay inverse-arp!router ospf 1 router-id 2.2.2.2 log-adjacency-changes network 2.2.2.0 0.0.0.255 area 0 network 123.1.1.0 0.0.0.255 area 0R3interface Loopback0 ip address 3.3.3.3 255.255.255.0 ip ospf network point-to-point!interface Serial1/3 ip address 123.1.1.3 255.255.255.0 encapsulation frame-relay ip ospf network point-to-multipoint serial restart-delay 0 frame-relay map ip 123.1.1.1 301 broadcast no frame-relay inverse-arp!router ospf 1 router-id 3.3.3.3 log-adjacency-changes network 3.3.3.0 0.0.0.255 area 0 network 123.1.1.0 0.0.0.255 area 0R2#sh ip ospf interface s1/2 Serial1/2 is up, line protocol is up Internet Address 123.1.1.2/24, Area 0 Process ID 1, Router ID 2.2.2.2, Network Type POINT_TO_MULTIPOINT, Cost: 64/ POINT_TO_MULTIPOINT 模式下，Hello 周期为30 秒 Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT, Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5 oob-resync timeout 120 Hello due in 00:00:06 Supports Link-local Signaling (LLS) Index 3/3, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 1.1.1.1 Suppress hello for 0 neighbor(s)R1#sh ip route ospf 2.0.0.0/24 is subnetted, 1 subnetsO 2.2.2.0 110/65 via 123.1.1.2, 00:18:40, Serial1/1.1 3.0.0.0/24 is subnetted, 1 subnetsO 3.3.3.0 110/65 via 123.1.1.3, 00:18:40, Serial1/1.1 123.0.0.0/8 is variably subnetted, 3 subnets, 2 masksO 123.1.1.3/32 110/64 via 123.1.1.3, 00:18:40, Serial1/1.1O 123.1.1.2/32 110/64 via 123.1.1.2, 00:18:40, Serial1/1.1R3#sh ip route ospf 1.0.0.0/24 is subnetted, 1 subnetsO 1.1.1.0 110/65 via 123.1.1.1, 00:20:29, Serial1/3 2.0.0.0/24 is subnetted, 1 subnetsO 2.2.2.0 110/129 via 123.1.1.1,