拓扑：
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分析：
1.配置IP，给每个设备配置两个环回地址，一个用来BGP邻居的建立（掩码32），一个用来模拟用户网段（掩码24，并修改接口类 型为broadcast）。路由器之间的互联网段自行设定。
2.IGP协议，在每个AS内部执行IGP协议，此处使用OSPF，AS200中需要建立OSPF，AS500中r9和r10需要建立OSPF。配置完后看OSPF邻居是否建立好。
3.BGP邻居建立，所有设备都执行BGP，进行全连接，打破IBGP水平分割的问题。配置完查看BGP邻居是否建立好。
4.路由传递，只传递模拟用户网段的路由信息。使用network或者重发布+路由策略进行路由传递。
5.同时拥有EBGP和IBGP邻居的设备，需要将下一跳改为自己的环回。
配置：
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1.配置IP：
r1
[r1]int l0
[r1-LoopBack0]ip ad 1.1.1.1 32
[r1-LoopBack0]int l1
[r1-LoopBack1]ip ad 192.168.1.1 24
[r1-LoopBack1]ospf n b
[r1]int g0/0/0
[r1-GigabitEthernet0/0/0]ip ad 12.0.0.1 30
[r1-GigabitEthernet0/0/0]int g0/0/1
[r1-GigabitEthernet0/0/1]ip ad 13.0.0.1 30
r2
[r2]int l0
[r2-LoopBack0]ip ad 2.2.2.2 32
[r2-LoopBack0]int l1
[r2-LoopBack1]ip ad 192.168.2.1 24
[r2-LoopBack1]ospf n b
[r2]int g0/0/0
[r2-GigabitEthernet0/0/0]ip ad 12.0.0.2 30
[r2-GigabitEthernet0/0/0]int g0/0/1
[r2-GigabitEthernet0/0/1]ip ad 24.0.0.1 30
r3
[r3]int l0
[r3-LoopBack0]ip ad 3.3.3.3 32
[r3-LoopBack0]int l1
[r3-LoopBack1]ip ad 192.168.3.1 24
[r3-LoopBack1]ospf n b
[r3]int g0/0/0
[r3-GigabitEthernet0/0/0]ip ad 13.0.0.2 30
[r3-GigabitEthernet0/0/0]int g0/0/1
[r3-GigabitEthernet0/0/1]ip ad 34.0.0.1 30
[r3-GigabitEthernet0/0/1]int g0/0/2
[r3-GigabitEthernet0/0/2]ip ad 35.0.0.1 30
r4
[r4]int l0
[r4-LoopBack0]ip ad 4.4.4.4 32
[r4-LoopBack0]int l1
[r4-LoopBack1]ip ad 192.168.4.1 24
[r4-LoopBack1]ospf n b
[r4]int g0/0/0
[r4-GigabitEthernet0/0/0]ip ad 24.0.0.2 30
[r4-GigabitEthernet0/0/0]int g0/0/01
[r4-GigabitEthernet0/0/1]ip ad 34.0.0.2 30
[r4-GigabitEthernet0/0/1]int g0/0/2
[r4-GigabitEthernet0/0/2]ip ad 45.0.0.1 30
[r4-GigabitEthernet0/0/2]int g1/0/0
[r4-GigabitEthernet1/0/0]ip ad 47.0.0.1 30
r5
[r5]int l0
[r5-LoopBack0]ip ad 5.5.5.5 32
[r5-LoopBack0]int l1
[r5-LoopBack1]ip ad 192.168.5.1 24
[r5-LoopBack1]ospf n b
[r5]int g0/0/0
[r5-GigabitEthernet0/0/0]ip ad 45.0.0.2 30
r6
[r6]int l0
[r6-LoopBack0]ip ad 6.6.6.6 32
[r6-LoopBack0]int l1
[r6-LoopBack1]ip ad 192.168.6.1 24
[r6-LoopBack1]ospf n b
[r6]int g0/0/0
[r6-GigabitEthernet0/0/0]ip ad 35.0.0.2 30
[r6-GigabitEthernet0/0/0]int g0/0/1
[r6-GigabitEthernet0/0/1]ip ad 67.0.0.1 30
[r6-GigabitEthernet0/0/1]int g0/0/2
[r6-GigabitEthernet0/0/2]ip ad 69.0.0.1 30
r7
[r7]int l0
[r7-LoopBack0]ip ad 7.7.7.7 32
[r7-LoopBack0]int l1
[r7-LoopBack1]ip ad 192.168.7.1 24
[r7-LoopBack1]ospf n b
[r7]int g0/00/0
[r7-GigabitEthernet0/0/0]ip ad 47.0.0.2 30
[r7-GigabitEthernet0/0/0]int g0/00/1
[r7-GigabitEthernet0/0/1]ip ad 67.0.0.2 30
[r7-GigabitEthernet0/0/1]int g1/0/0
[r7-GigabitEthernet1/0/0]ip ad 107.0.0.1 30
[r7-GigabitEthernet1/0/0]int g0/0/2
[r7-GigabitEthernet0/0/2]ip ad 78.0.0.1 30
r8
[r8]int l0
[r8-LoopBack0]ip ad 8.8.8.8 32
[r8-LoopBack0]int l1
[r8-LoopBack1]ip ad 192.168.8.1 24
[r8-LoopBack1]ospf n b
[r8]int g0/0/0
[r8-GigabitEthernet0/0/0]ip ad 78.0.0.2 30
r9
[r9]int l0
[r9-LoopBack0]ip ad 9.9.9.9 32
[r9-LoopBack0]int l1
[r9-LoopBack1]ip ad 192.168.9.1 24
[r9-LoopBack1]ospf n b
[r9]int g0/0/0
[r9-GigabitEthernet0/0/0]ip ad 69.0.0.2 30
[r9-GigabitEthernet0/0/0]int g0/0/1
[r9-GigabitEthernet0/0/1]ip ad 109.0.0.1 30
r10
[r10]int l0
[r10-LoopBack0]ip ad 10.10.10.10 32
[r10-LoopBack0]int l1
[r10-LoopBack1]ip ad 192.168.10.1 24
[r10-LoopBack1]ospf n b
[r10]int g0/0/0
[r10-GigabitEthernet0/0/0]ip ad 107.0.0.2 30
[r10-GigabitEthernet0/0/0]int g0/0/1
[r10-GigabitEthernet0/0/1]ip ad 109.0.0.2 30
2.IGP配置
r2
[r2]ospf 1 r 2.2.2.2
[r2-ospf-1]area 0
[r2-ospf-1-area-0.0.0.0]net 2.2.2.2 0.0.0.0
[r2-ospf-1-area-0.0.0.0]net 192.168.2.1 0.0.0.0
[r2-ospf-1-area-0.0.0.0]net 24.0.0.1 0.0.0.0
r3
[r3]ospf 1 r 3.3.3.3
[r3-ospf-1]area 0
[r3-ospf-1-area-0.0.0.0]net 3.3.3.3 0.0.0.0
[r3-ospf-1-area-0.0.0.0]net 192.168.3.1 0.0.0.0
[r3-ospf-1-area-0.0.0.0]net 34.0.0.1 0.0.0.0
r4
[r4]ospf 1 r 4.4.4.4
[r4-ospf-1]area 0
[r4-ospf-1-area-0.0.0.0]net 4.4.4.4 0.0.0.0
[r4-ospf-1-area-0.0.0.0]net 192.168.4.1 0.0.0.0
[r4-ospf-1-area-0.0.0.0]net 24.0.0.2 0.0.0.0
[r4-ospf-1-area-0.0.0.0]net 34.0.0.2 0.0.0.0
r9
[r9]ospf 1 r 9.9.9.9
[r9-ospf-1]area 0
[r9-ospf-1-area-0.0.0.0]net 9.9.9.9 0.0.0.0
[r9-ospf-1-area-0.0.0.0]net 192.168.9.1 0.00.0.0
[r9-ospf-1-area-0.0.0.0]net 109.0.0.1 0.0.0.0
r10
[r10]ospf 1 r 10.10.10.10
[r10-ospf-1]area 0
[r10-ospf-1-area-0.0.0.0]net 10.10.10.10 0.0.0.0
[r10-ospf-1-area-0.0.0.0]net 192.168.10.1 0.0.0.0
[r10-ospf-1-area-0.0.0.0]net 109.0.0.2 0.0.0.0
检查邻居建立关系
3.BGP邻居建立
r1
[r1]bgp 100
[r1-bgp]r 1.1.1.1
[r1-bgp]peer 12.0.0.2 as-number 200
[r1-bgp]peer 13.0.0.2 as-number 200
r2
[r2]bgp 200
[r2-bgp]r 2.2.2.2
[r2-bgp]peer 12.0.0.1 as-number 100
[r2-bgp]peer 4.4.4.4 as-number 200
[r2-bgp]peer 3.3.3.3 as-number 200
[r2-bgp]peer 4.4.4.4 connect-interface l0
[r2-bgp]peer 3.3.3.3 connect-interface l0
r3
[r3]bgp 200
[r3-bgp]r 3.3.3.3
[r3-bgp]peer 13.0.0.1 as-number 100
[r3-bgp]peer 2.2.2.2 as-number 200
[r3-bgp]peer 4.4.4.4 as-number 200
[r3-bgp]peer 2.2.2.2 connect-interface l0
[r3-bgp]peer 4.4.4.4 connect-interface l0
[r3-bgp]peer 35.0.0.2 as-number 300
r4
[r4]bgp 200
[r4-bgp]r 4.4.4.4
[r4-bgp]peer 2.2.2.2 as-number 200
[r4-bgp]peer 3.3.3.3 as-number 200
[r4-bgp]peer 2.2.2.2 connect-interface l0
[r4-bgp]peer 3.3.3.3 connect-interface l0
[r4-bgp]peer 47.0.0.2 as-number 400
[r4-bgp]peer 45.0.0.2 as-number 300
r5
[r5]bgp 300
[r5-bgp]r 5.5.5.5
[r5-bgp]peer 45.0.0.1 as-number 200
r6
[r6]bgp 300
[r6-bgp]r 6.6.6.6
[r6-bgp]peer 35.0.0.1 as-number 200
[r6-bgp]peer 67.0.0.2 as-number 400
[r6-bgp]peer 69.0.0.2 as-number 500
r7
[r7]bgp 400
[r7-bgp]r 7.7.7.7
[r7-bgp]peer 47.0.0.1 as-number 200
[r7-bgp]peer 67.0.0.1 as-number 300
[r7-bgp]peer 107.0.0.2 as-number 500
[r7-bgp]peer 78.0.0.2 as-number 500
r8
[r8]bgp 500
[r8-bgp]r 8.8.8.8
[r8-bgp]peer 78.0.0.1 as-number 400
r9
[r9]bgp 500
[r9-bgp]r 9.9.9.9
[r9-bgp]peer 69.0.0.1 as-number 300
[r9-bgp]peer 10.10.10.10 as-number 500
[r9-bgp]peer 10.10.10.10 connect-interface l0
r10
[r10]bgp 500
[r10-bgp]r 10.10.10.10
[r10-bgp]peer 107.0.0.1 as-number 400
[r10-bgp]peer 9.9.9.9 as-number 500
[r10-bgp]peer 9.9.9.9 connect-interface l0
查看邻居是否建立好
4.路由发布
r1
[r1-bgp]net 192.168.1.1 24
r2
[r2]ip ip-prefix aa permit 192.168.0.0 21 greater-equal 24 less-equal 24
[r2]route-policy aa permit node 10
[r2-route-policy]if-match ip-prefix aa
[r2-bgp]import-route direct route-policy aa
[r2-bgp]import-route ospf 1 route-policy aa
r3
[r3]route-policy aa permit node 10
[r3-route-policy]if-match ip-prefix aa
[r3-route-policy]ip ip-prefix aa index 10 permit 192.168.0.0 21 greater-equal 24
less-equal 24
[r3]bgp 200
[r3-bgp]import-route direct route-policy aa
[r3-bgp]import-route ospf 1 route-policy aa
r4
[r4]route-policy aa permit node 10
[r4-route-policy]if-match ip-prefix aa
[r4-route-policy]ip ip-prefix aa index 10 permit 192.168.0.0 21 greater-equal 24
less-equal 24
[r4]bgp 200
[r4-bgp]import-route direct route-policy aa
[r4-bgp]import-route ospf 1 route-policy aa
r5
[r5-bgp]net 192.168.5.1 24
r6
[r6-bgp]net 192.168.6.1 24
r7
[r7-bgp]net 192.168.7.1 24
r8
[r8-bgp]net 192.168.8.1 24
r9
[r9-bgp]net 192.168.9.1 24
[r9-bgp]net 192.168.10.1 24
r10
[r10-bgp]net 192.168.10.1 24
[r10-bgp]net 192.168.9.1 24
5.同时有IBGP和EBGP邻居的，发送路由时要将下一跳改为自己
r2
[r2-bgp]peer 3.3.3.3 next-hop-local
[r2-bgp]peer 4.4.4.4 next-hop-local
r3
[r3-bgp]peer 2.2.2.2 next-hop-local
[r3-bgp]peer 4.4.4.4 next-hop-local
r4
[r4-bgp]peer 2.2.2.2 next-hop-local
[r4-bgp]peer 3.3.3.3 next-hop-local
r9
[r9-bgp]peer 10.10.10.10 next-hop-local
r10
[r10-bgp]peer 9.9.9.9 next-hop-local
r10
[r10-bgp]peer 107.0.0.1 allow-as-loop 2
r9
[r9-bgp]peer 69.0.0.1 allow-as-loop 2
r8
[r8-bgp]peer 78.0.0.1 allow-as-loop 2
r6
[r6-bgp]peer 35.0.0.1 allow-as-loop 2
r5
[r5-bgp]peer 45.0.0.1 allow-as-loop 2
