BGP组网实验_IBGP全连接与路由反射器.doc

组网一：BGP路由黑洞问题拓扑图：Ip地址配置：R1：interface Loopback0 ip address 10.0.0.1 255.255.255.255!interface Serial0/0 ip address 10.0.1.6 255.255.255.252 serial restart-delay 0 no dce-terminal-timing-enable!interface Serial0/1 ip address 10.0.15.1 255.255.255.252 serial restart-delay 0 no dce-terminal-timing-enableR2：interface Loopback0 ip address 10.0.0.2 255.255.255.255!interface Serial0/0 ip address 10.0.1.10 255.255.255.252 serial restart-delay 0 no dce-terminal-timing-enable!interface Serial0/1 ip address 10.0.26.1 255.255.255.252 serial restart-delay 0 no dce-terminal-timing-enabler3：interface Loopback0 ip address 10.0.0.3 255.255.255.255!interface Serial0/0 ip address 10.0.1.5 255.255.255.252 serial restart-delay 0 no dce-terminal-timing-enableinterface FastEthernet1/0 ip address 10.0.1.1 255.255.255.252 ip ospf network point-to-point /*配置成点对点类型 ip ospf cost 100 /*ospf cost值配为100 duplex auto speed auto!interface Ethernet3/0 ip address 10.3.3.1 255.255.255.0 half-duplexR4：interface FastEthernet1/0 ip address 10.0.1.2 255.255.255.252 ip ospf network point-to-point /*接口类型点对点 ip ospf cost 100 /*cost为100 duplex auto speed auto!interface Ethernet3/0 ip address 10.3.4.1 255.255.255.0 half-duplexinterface Loopback0 ip address 10.0.0.4 255.255.255.255!interface Serial0/0 ip address 10.0.1.9 255.255.255.252 serial restart-delay 0 no dce-terminal-timing-enableR5：interface Loopback0 ip address 10.5.0.1 255.255.255.255!interface Serial0/0 ip address 10.0.15.2 255.255.255.252 serial restart-delay 0 no dce-terminal-timing-enableinterface Ethernet3/0 ip address 10.5.5.1 255.255.255.0 half-duplexR6：interface Ethernet3/0 ip address 10.6.6.1 255.255.255.0 half-duplexinterface Loopback0 ip address 10.6.0.1 255.255.255.255!interface Serial0/0 ip address 10.0.26.2 255.255.255.252 serial restart-delay 0 no dce-terminal-timing-enableIGP配置：R1router ospf 1 router-id 1.1.1.1 log-adjacency-changes network 10.0.0.1 0.0.0.0 area 0 network 10.0.1.4 0.0.0.3 area 0 network 10.0.15.0 0.0.0.3 area 0R2router ospf 1 router-id 2.2.2.2 log-adjacency-changes network 10.0.0.2 0.0.0.0 area 0 network 10.0.1.8 0.0.0.3 area 0 network 10.0.26.0 0.0.0.3 area 0R3：router ospf 1 router-id 3.3.3.3 log-adjacency-changes network 10.0.0.3 0.0.0.0 area 0 network 10.0.1.0 0.0.0.3 area 0 network 10.0.1.4 0.0.0.3 area 0 network 10.3.3.0 0.0.0.255 area 0R4：router ospf 1 router-id 4.4.4.4 log-adjacency-changes network 10.0.0.4 0.0.0.0 area 0 network 10.0.1.0 0.0.0.3 area 0 network 10.0.1.8 0.0.0.3 area 0 network 10.3.4.0 0.0.0.255 area 0BGP配置：R1：router bgp 65000 no synchronization bgp log-neighbor-changes network 10.0.0.0 mask 255.255.0.0 network 10.3.0.0 mask 255.255.0.0 neighbor 10.0.0.2 remote-as 65000 neighbor 10.0.0.2 update-source Loopback0 neighbor 10.0.0.2 next-hop-self neighbor 10.0.15.2 remote-as 65001 no auto-summaryR2：router bgp 65000 no synchronization bgp log-neighbor-changes network 10.0.0.0 mask 255.255.0.0 network 10.3.0.0 mask 255.255.0.0 neighbor 10.0.0.1 remote-as 65000 neighbor 10.0.0.1 update-source Loopback0 neighbor 10.0.0.1 next-hop-self neighbor 10.0.26.2 remote-as 65002 no auto-summaryR5：router bgp 65001 no synchronization bgp log-neighbor-changes network 10.5.0.0 mask 255.255.0.0 neighbor 10.0.15.1 remote-as 65000 no auto-summaryR6：router bgp 65002 no synchronization bgp log-neighbor-changes network 10.6.0.0 mask 255.255.0.0 neighbor 10.0.26.1 remote-as 65000 no auto-summary以10.5.5.1为源traceroute 10.6.6.1，查看数据包经过的路径，同时在r3上debug ip packet：r5#traceroute 10.6.6.1 source 10.5.5.1Type escape sequence to abort.Tracing the route to 10.6.6.1 1 10.0.15.1 AS 65000 36 msec 60 msec 56 msec /*数据包首先经过了r1 2 * * * 3 * * *r3#debug ip packet*Mar 1 01:48:46.291: IP: s=10.0.1.5 (local), d=10.5.5.1, len 56, unroutabler3#*Mar 1 01:48:48.299: IP: s=10.0.1.6 (Serial0/0), d=224.0.0.5, len 80, rcvd 0r3#*Mar 1 01:48:49.303: IP: s=10.0.1.5 (local), d=10.5.5.1, len 56, unroutable /*到r3后查看路由表后发现目标不可达*Mar 1 01:48:49.763: IP: s=10.0.1.2 (FastEthernet1/0), d=224.0.0.5, len 80, rcvd 0broad/multicast*Mar 1 01:48:52.303: IP: s=10.0.1.5 (local), d=10.5.5.1, len 56, unroutable*Mar 1 01:48:55.311: IP: s=10.5.5.1 (Serial0/0), d=10.6.6.1, len 28, unroutable*Mar 1 01:48:55.315: IP: s=10.0.1.5 (local), d=10.5.5.1, len 56, unroutable*Mar 1 01:48:58.291: IP: s=10.0.1.6 (Serial0/0), d=224.0.0.5, len 80, rcvd 0*Mar 1 01:48:58.387: IP: s=10.5.5.1 (Serial0/0), d=10.6.6.1, len 28, unroutable*Mar 1 01:48:58.391: IP: s=10.0.1.5 (local), d=10.5.5.1, len 56, unroutable黑洞分析：R5的路由表：r5#show ip route 10.0.0.0/8 is variably subnetted, 7 subnets, 4 masksC 10.0.15.0/30 is directly connected, Serial0/0B 10.3.0.0/16 20/0 via 10.0.15.1, 00:32:08C 10.5.5.0/24 is directly connected, Ethernet3/0B 10.0.0.0/16 20/0 via 10.0.15.1, 00:32:08B 10.6.0.0/16 20/0 via 10.0.15.1, 00:30:55/*R5上有去往10.6.0.0的路由下一跳为R1C 10.5.0.1/32 is directly connected, Loopback0S 10.5.0.0/16 is directly connected, Null0查看R1路由表：rt1#show ip route 10.0.0.0/8 is variably subnetted, 15 subnets, 4 masksO 10.0.1.8/30 110/228 via 10.0.1.5, 00:37:53, Serial0/0C 10.0.15.0/30 is directly connected, Serial0/1O 10.0.0.2/32 110/229 via 10.0.1.5, 00:37:53, Serial0/0S 10.3.0.0/16 is directly connected, Null0O 10.0.0.3/32 110/65 via 10.0.1.5, 00:37:53, Serial0/0O 10.3.3.0/24 110/74 via 10.0.1.5, 00:37:53, Serial0/0S 10.0.0.0/16 is directly connected, Null0O 10.0.1.0/30 110/164 via 10.0.1.5, 00:37:53, Serial0/0C 10.0.0.1/32 is directly connected, Loopback0B 10.6.0.0/16 200/0 via 10.0.0.2, 00:32:59/*通过递归查找发现去往10.6.0.0的路由直连下一跳为R3的10.0.1.5O 10.3.4.0/24 110/174 via 10.0.1.5, 00:37:53, Serial0/0O 10.0.0.4/32 110/165 via 10.0.1.5, 00:37:53, Serial0/0B 10.5.0.0/16 20/0 via 10.0.15.2, 00:34:13C 10.0.1.4/30 is directly connected, Serial0/0O 10.0.26.0/30 110/292 via 10.0.1.5, 00:37:54, Serial0/0查看R3的路由表：r3#show ip route 10.0.0.0/8 is variably subnetted, 11 subnets, 3 masksO 10.0.1.8/30 110/164 via 10.0.1.2, 00:40:32, FastEthernet1/0O 10.0.15.0/30 110/128 via 10.0.1.6, 00:40:32, Serial0/0O 10.0.0.2/32 110/165 via 10.0.1.2, 00:40:32, FastEthernet1/0C 10.0.0.3/32 is directly connected, Loopback0C 10.3.3.0/24 is directly connected, Ethernet3/0C 10.0.1.0/30 is directly connected, FastEthernet1/0O 10.0.0.1/32 110/65 via 10.0.1.6, 00:40:32, Serial0/0O 10.3.4.0/24 110/110 via 10.0.1.2, 00:40:32, FastEthernet1/0O 10.0.0.4/32 110/101 via 10.0.1.2, 00:40:32, FastEthernet1/0C 10.0.1.4/30 is directly connected, Serial0/0O 10.0.26.0/30 110/228 via 10.0.1.2, 00:40:32, FastEthernet1/0/*在R3上只有IGP路由，不可能学习到10.6.0.0的路由数据包在此丢弃.组网二：BGP同步对同步的分析理解：1.两种状态非同步状态下，会将从IBGP学到的路由通告给他的EBGP邻居。同步状态下，只将达到同步的路由通告给它的EBGP邻居，即如果一条从IBGP学到的路由，也能从IGP学到，那么这条路由将通告给它的EGP邻居2怎样达到同步将从EBGP学到的路由重发布至IGP中3.将BGP路由重发布进IGP的危害BGP路由一般比较复杂，往往会超过IGP所能承受的极限，导致崩溃。4.什么情况下可以关同步本Asnei yunxing MPLS,且本AS不是transmit AS，本as内的所有提供转发服务的路由器都能从BGP学到其他AS的路由rt1#show ip bgp Network Next Hop Metric LocPrf Weight Path* i10.0.0.0/16 10.0.0.2 0 100 0 i* 0.0.0.0 0 32768 i* i10.3.0.0/16 10.0.0.2 0 100 0 i* 0.0.0.0 0 32768 i* 10.5.0.0/16 10.0.15.2 0 0 65001 i*i10.6.0.0/16 10.0.0.2 0 100 0 65002 i/*标记下与开同步后进行对比r2#show ip bgp Network Next Hop Metric LocPrf Weight Path* 10.0.0.0/16 0.0.0.0 0 32768 i* i 10.0.0.1 0 100 0 i* 10.3.0.0/16 0.0.0.0 0 32768 i* i 10.0.0.1 0 100 0 i*i10.5.0.0/16 10.0.0.1 0 100 0 65001 i* 10.6.0.0/16 10.0.26.2 0 0 65002 i/*标记好进行对比r5#show ip bgp Network Next Hop Metric LocPrf Weight Path* 10.0.0.0/16 10.0.15.1 0 0 65000 i* 10.3.0.0/16 10.0.15.1 0 0 65000 i* 10.5.0.0/16 0.0.0.0 0 32768 ir6#show ip bgp Network Next Hop Metric LocPrf Weight Path* 10.0.0.0/16 10.0.26.1 0 0 65000 i* 10.3.0.0/16 10.0.26.1 0 0 65000 i* 10.6.0.0/16 0.0.0.0 0 32768 i在实验组网一的配置下，是关闭同步的，所以开同步：rt1(config)#router bgp 65000rt1(config-router)#synchronizationr2(config)#router bgp 65000r2(config-router)#syn查看开启同步后bgp表的变化：rt1#show ip bgp Network Next Hop Metric LocPrf Weight Path* i10.0.0.0/16 10.0.0.2 0 100 0 i* 0.0.0.0 0 32768 i* i10.3.0.0/16 10.0.0.2 0 100 0 i* 0.0.0.0 0 32768 i* 10.5.0.0/16 10.0.15.2 0 0 65001 i* i10.6.0.0/16 10.0.0.2 0 100 0 65002 i/*因为10.6.0.0网段是r2通bgp从r6学到的，再通过ibgp告诉r1，但r1不能从igp学到这条路由，所以这条路由不能进路由表rt1#show ip route 10.0.0.0/8 is variably subnetted, 14 subnets, 4 masksO 10.0.1.8/30 110/228 via 10.0.1.5, 01:20:07, Serial0/0C 10.0.15.0/30 is directly connected, Serial0/1O 10.0.0.2/32 110/229 via 10.0.1.5, 01:20:07, Serial0/0S 10.3.0.0/16 is directly connected, Null0O 10.0.0.3/32 110/65 via 10.0.1.5, 01:20:07, Serial0/0O 10.3.3.0/24 110/74 via 10.0.1.5, 01:20:07, Serial0/0S 10.0.0.0/16 is directly connected, Null0O 10.0.1.0/30 110/164 via 10.0.1.5, 01:20:07, Serial0/0C 10.0.0.1/32 is directly connected, Loopback0O 10.3.4.0/24 110/174 via 10.0.1.5, 01:20:07, Serial0/0O 10.0.0.4/32 110/165 via 10.0.1.5, 01:20:07, Serial0/0B 10.5.0.0/16 20/0 via 10.0.15.2, 00:19:18C 10.0.1.4/30 is directly connected, Serial0/0O 10.0.26.0/30 110/292 via 10.0.1.5, 01:20:08, Serial0/0/*路由表中没有了去往10.6.0.0的路由r2#show ip bgp Network Next Hop Metric LocPrf Weight Path* 10.0.0.0/16 0.0.0.0 0 32768 i* i 10.0.0.1 0 100 0 i* 10.3.0.0/16 0.0.0.0 0 32768 i* i 10.0.0.1 0 100 0 i* i10.5.0.0/16 10.0.0.1 0 100 0 65001 i/*同样r2上也没有了关于10.5.0.0的路由* 10.6.0.0/16 10.0.26.2 0 0 65002 i解决方法是做重发布：将bgp路由重发布进igprt1(config)#router ospf 1rt1(config-router)#redistribute bgp 65000 subnets metric 4000r2(config)#router ospf 1r2(config-router)#redistribute bgp 65000 subnets metric 4000中间清bgp表，然后要等一小会再次查看bgp表：rt1#show ip bgp Network Next Hop Metric LocPrf Weight Path* i10.0.0.0/16 10.0.0.2 0 100 0 i* 0.0.0.0 0 32768 i* i10.3.0.0/16 10.0.0.2 0 100 0 i* 0.0.0.0 0 32768 i* 10.5.0.0/16 10.0.15.2 0 0 65001 iri10.6.0.0/16 10.0.0.2 0 100 0 65002 ir2#show ip bgp Network Next Hop Metric LocPrf Weight Path* 10.0.0.0/16 0.0.0.0 0 32768 i* i 10.0.0.1 0 100 0 i* 10.3.0.0/16 0.0.0.0 0 32768 i* i 10.0.0.1 0 100 0 iri10.5.0.0/16 10.0.0.1 0 100 0 65001 i* 10.6.0.0/16 10.0.26.2 0 0 65002 i由于作了重发布，r3将会以ospf的路由学到r5和r6的路由r5#ping 10.6.6.1 source 10.5.5.1Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 10.6.6.1, timeout is 2 seconds:Packet sent with a source address of 10.5.5.1 !Success rate is 100 percent (5/5), round-trip min/avg/max = 72/96/120 ms组网三：IBGP全连接取消BGP至IGP的重发布，关同步R1：router bgp 65000 no synchronization bgp log-neighbor-changes network 10.0.0.0 mask 255.255.0.0 /*发布汇总路由 network 10.3.0.0 mask 255.255.0.0 neighbor as65000 peer-group /*定义名为as65000的peer-group neighbor as65000 remote-as 65000 /*定义将在AS65000内充当这组共享路由器中的成员 neighbor as65000 update-source Loopback0 /*定义建立BGP邻居的接口为loopback0接口 neighbor as65000 next-hop-self /*定义发送的下一跳为自己 neighbor 10.0.0.2 peer-group as65000 neighbor 10.0.0.3 peer-group as65000 neighbor 10.0.0.4 peer-group as65000 neighbor 10.0.15.2 remote-as 65001 no auto-summaryR2：router bgp 65000 no synchronization bgp log-neighbor-changes network 10.0.0.0 mask 255.255.0.0 network 10.3.0.0 mask 255.255.0.0 neighbor as65000 peer-group neighbor as65000 remote-as 65000 neighbor as65000 update-source Loopback0 neighbor as65000 next-hop-self neighbor 10.0.0.1 peer-group as65000 neighbor 10.0.0.3 peer-group as65000 neighbor 10.0.0.4 peer-group as65000 neighbor 10.0.26.2 remote-as 65002 no auto-summaryR3：router bgp 65000 no synchronization bgp log-neighbor-changes neighbor as65000 peer-group neighbor as65000 remote-as 65000 neighbor as65000 update-source Loopback0 neighbor as65000 next-hop-self neighbor 10.0.0.1 peer-group as65000 neighbor 10.0.0.2 peer-group as65000 neighbor 10.0.0.4 peer-group as65000 no auto-summaryR4：router bgp 65000 no synchronization bgp log-neighbor-changes neighbor as65000 peer-group neighbor as65000 remote-as 65000 neighbor as65000 update-source Loopback0 neighbor as65000 next-hop-self neighbor 10.0.0.1 peer-group as65000 neighbor 10.0.0.2 peer-group as65000 neighbor 10.0.0.3 peer-group as65000 no auto-summaryR5：router bgp 65001 no synchronization bgp log-neighbor-changes network 10.5.0.0 mask 255.255.0.0 neighbor 10.0.15.1 remote-as 65000 no auto-summaryR6：router bgp 65002 no synchronization bgp log-neighbor-changes network 10.6.0.0 mask 255.255.0.0 neighbor 10.0.26.1 remote-as 65000 no auto-summary查看各路由器BGP路由表rt1#show ip route bgp 10.0.0.0/8 is variably subnetted, 13 subnets, 4 masksB 10.6.0.0/16 200/0 via 10.0.0.2, 00:05:23B 10.5.0.0/16 20/0 via 10.0.15.2, 00:33:30r2#show ip route bgp 10.0.0.0/8 is variably subnetted, 13 subnets, 4 masksB 10.6.0.0/16 20/0 via 10.0.26.2, 00:06:06B 10.5.0.0/16 200/0 via 10.0.0.1, 00:06:06r3#show ip route bgp 10.0.0.0/8 is variably subnetted, 13 subnets, 4 masksB 10.6.0.0/16 200/0 via 10.0.0.2, 00:06:23B 10.5.0.0/16 200/0 via 10.0.0.1, 00:34:31r4#show ip route bgp 10.0.0.0/8 is variably subnetted, 13 subnets, 4 masksB 10.6.0.0/16 200/0 via 10.0.0.2, 00:06:37B 10.5.0.0/16 200/0 via 10.0.0.1, 00:34:44r5#show ip route bgp 10.0.0.0/8 is variably subnetted, 5 subnets, 4 masksB 10.6.0.0/16 20/0 via 10.0.15.1, 00:07:35r6#show ip route bgp 10.0.0.0/8 is variably subnetted, 5 subnets, 4 masksB 10.5.0.0/16 20/0 via 10.0.26.1, 00:07:15/*R5和R6都能通过IGP学到对方网段查看全局路由表：rt1#show ip route 10.0.0.0/8 is variably subnetted, 13 subnets, 4 masksO 10.0.1.8/30 110/228 via 10.0.1.5, 00:56:13, Serial0/0C 10.0.15.0/30 is directly connected, Serial0/1O 10.0.0.2/32 110/229 via 10.0.1.5, 00:56:13, Serial0/0O 10.0.0.3/32 110/65 via 10.0.1.5, 00:56:13, Serial0/0O 10.3.3.0/24 110/74 via 10.0.1.5, 00:56:13, Serial0/0O 10.0.1.0/30 110/164 via 10.0.1.5, 00:56:13, Serial0/0C 10.0.0.1/32 is directly connected, Loopback0B 10.6.0.0/16 200/0 via 10.0.0.2, 00:10:19O 10.3.4.0/24 110/174 via 10.0.1.5, 00:56:13, Serial0/0O 10.0.0.4/32 110/165 via 10.0.1.5, 00:56:13, Serial0/0B 10.5.0.0/16 20/0 via 10.0.15.2, 00:38:27C 10.0.1.4/30 is directly connected, Serial0/0O 10.0.26.0/30 110/292 via 10.0.1.5, 00:56:14, Serial0/0r2#show ip route 10.0.0.0/8 is variably subnetted, 13 subnets, 4 masksC 10.0.1.8/30 is directly connected, Serial0/0O 10.0.15.0/30 110/292 via 10.0.1.9, 00:56:20, Serial0/0C 10.0.0.2/32 is directly connected, Loopback0O 10.0.0.3/32 110/165 via 10.0.1.9, 00:56:20, Serial0/0O 10.3.3.0/24 110/174 via 10.0.1.9, 00:56:20, Serial0/0O 10.0.1.0/30 110/164 via 10.0.1.9, 00:56:20, Serial0/0O 10.0.0.1/32 110/229 via 10.0.1.9, 00:56:20, Serial0/0B 10.6.0.0/16 20/0 via 10.0.26.2, 00:10:26O 10.3.4.0/24 110/74 via 10.0.1.9, 00:56:20, Serial0/0O 10.0.0.4/32 110/65 via 10.0.1.9, 00:56:20, Serial0/0B 10.5.0.0/16 200/0 via 10.0.0.1, 00:10:26O 10.0.1.4/30 110/228 via 10.0.1.9, 00:56:20, Serial0/0C 10.0.26.0/30 is directly connected, Serial0/1r3#show ip route 10.0.0.0/8 is variably subnetted, 13 subnets, 4 masksO 10.0.1.8/30 110/164 via 10.0.1.2, 00:56:24, FastEthernet1/0O 10.0.15.0/30 110/128 via 10.0.1.6, 00:56:24, Serial0/0O 10.0.0.2/32 110/165 via 10.0.1.2, 00:56:24, FastEth