BGP邻居建立路由发布实验

1.配置IP地址

复制代码

[r1]int l 0
[r1-LoopBack0]ip address 1.1.1.1 32
[r1]int l 1
[r1-LoopBack1]ip address 192.168.1.1 24
[r1]int g 0/0/0
[r1-GigabitEthernet0/0/0]ip address 12.0.0.1 24
[r1]int g 0/0/1
[r1-GigabitEthernet0/0/1]ip address 13.0.0.1 24

[r2]int l 0
[r2-LoopBack0]ip address 2.2.2.2 32
[r2]int l 1
[r2-LoopBack1]ip address 192.168.2.1 24
[r2]int g 0/0/0
[r2-GigabitEthernet0/0/0]ip address 12.0.0.2 24
[r2]int g 0/0/1
[r2-GigabitEthernet0/0/1]ip address 24.0.0.2 24

[r3]int l 0
[r3-LoopBack0]ip address 3.3.3.3 32
[r3]int l 1
[r3-LoopBack1]ip address 192.168.3.1 24
[r3]int g 0/0/0
[r3-GigabitEthernet0/0/0]ip address 13.0.0.3 24
[r3]int g 0/0/1
[r3-GigabitEthernet0/0/1]ip address 34.0.0.3 24
[r3]int g 0/0/2
[r3-GigabitEthernet0/0/1]ip address 36.0.0.3 24

[r4]int l 0
[r4-LoopBack0]ip address 4.4.4.4 32
[r4]int l 1
[r4-LoopBack1]ip address 192.168.4.1 24
[r4]int g 0/0/0
[r4-GigabitEthernet0/0/0]ip address 24.0.0.4 24
[r4]int g 0/0/1
[r4-GigabitEthernet0/0/1]ip address 34.0.0.4 24
[r4]int g 0/0/2
[r4-GigabitEthernet0/0/1]ip address 45.0.0.4 24
[r4]int g 1/0/0
[r4-GigabitEthernet0/0/1]ip address 47.0.0.4 24

[r5]int l 0
[r5-LoopBack0]ip address 5.5.5.5 32
[r5]int l 1
[r5-LoopBack1]ip address 192.168.5.1 24
[r5]int g 0/0/0
[r5-GigabitEthernet0/0/0]ip address 45.0.0.5 24

[r6]int l 0
[r6-LoopBack0]ip address 6.6.6.6 32
[r6]int l 1
[r6-LoopBack1]ip address 192.168.6.1 24
[r6]int g 0/0/0
[r6-GigabitEthernet0/0/0]ip address 36.0.0.6 24
[r6]int g 0/0/1
[r6-GigabitEthernet0/0/1]ip address 67.0.0.6 24
[r6]int g 0/0/2
[r6-GigabitEthernet0/0/1]ip address 69.0.0.6 24

[r7]int l 0
[r7-LoopBack0]ip address 7.7.7.7 32
[r7]int l 1
[r7-LoopBack1]ip address 192.168.7.1 24
[r7]int g 0/0/0
[r7-GigabitEthernet0/0/0]ip address 47.0.0.7 24
[r7]int g 0/0/1
[r7-GigabitEthernet0/0/1]ip address 67.0.0.7 24
[r7]int g 0/0/2
[r7-GigabitEthernet0/0/1]ip address 78.0.0.7 24
[r7]int g 1/0/0
[r7-GigabitEthernet0/0/1]ip address 107.0.0.7 24

[r8]int l 0
[r8-LoopBack0]ip address 8.8.8.8 32
[r8]int l 1
[r8-LoopBack1]ip address 192.168.8.1 24
[r8]int g 0/0/0
[r8-GigabitEthernet0/0/0]ip address 78.0.0.8 24

[r9]int l 0
[r9-LoopBack0]ip address 9.9.9.9 32
[r9]int l 1
[r9-LoopBack1]ip address 192.168.9.1 24
[r9]int g 0/0/0
[r9-GigabitEthernet0/0/0]ip address 69.0.0.9 24
[r9]int g 0/0/1
[r9-GigabitEthernet0/0/1]ip address 109.0.0.9 24

[r10]int l 0
[r10-LoopBack0]ip address 10.10.10.10 32
[r10]int l 1
[r10-LoopBack1]ip address 192.168.10.1 24
[r10]int g 0/0/0
[r10-GigabitEthernet0/0/0]ip address 107.0.0.10 24
[r10]int g 0/0/1
[r10-GigabitEthernet0/0/1]ip address 109.0.0.10 24

2.运行IGP协议

as外部网段不用被宣告进OSPF协议

复制代码

[r2]ospf 1 router-id 2.2.2.2	
[r2-ospf-1]area 0
[r2-ospf-1-area-0.0.0.0]network 2.2.2.2 0.0.0.0
[r2-ospf-1-area-0.0.0.0]network 24.0.0.2 0.0.0.0
[r2-ospf-1-area-0.0.0.0]network 192.168.2.1 0.0.0.0
[r2]int l 1
[r2-LoopBack1]ospf network-type broadcast    ---模拟用户网段

[r3]ospf 1 router-id 3.3.3.3
[r3-ospf-1]area 0
[r3-ospf-1-area-0.0.0.0]network 3.3.3.3 0.0.0.0
[r3-ospf-1-area-0.0.0.0]network 34.0.0.3 0.0.0.0
[r3-ospf-1-area-0.0.0.0]network 192.168.3.1 0.0.0.0
[r3]int l 1
[r3-LoopBack1]ospf network-type broadcast

[r4]ospf 1 router-id 4.4.4.4	
[r4-ospf-1]area 0
[r4-ospf-1-area-0.0.0.0]network 4.4.4.4 0.0.0.0
[r4-ospf-1-area-0.0.0.0]network 24.0.0.4 0.0.0.0
[r4-ospf-1-area-0.0.0.0]network 34.0.0.4 0.0.0.0
[r4-ospf-1-area-0.0.0.0]network 192.168.4.1 0.0.0.0
[r4]int l 1
[r4-LoopBack1]ospf network-type broadcast

[r9]ospf 1 router-id 9.9.9.9
[r9-ospf-1]area 0
[r9-ospf-1-area-0.0.0.0]network 9.9.9.9 0.0.0.0
[r9-ospf-1-area-0.0.0.0]network 109.0.0.9 0.0.0.0
[r9-ospf-1-area-0.0.0.0]network 192.168.9.1 0.0.0.0
[r9]int l 1
[r9-LoopBack1]ospf network-type broadcast

[r10]ospf 1 router-id 10.10.10.10
[r10-ospf-1]area 0
[r10-ospf-1-area-0.0.0.0]network 10.10.10.10 0.0.0.0
[r10-ospf-1-area-0.0.0.0]network 109.0.0.10 0.0.0.0
[r10-ospf-1-area-0.0.0.0]network 192.168.10.1 0.0.0.0
[r10]int l 1
[r10-LoopBack1]ospf network-type broadcast

3.运行BGP协议

复制代码

[r1]bgp 100
[r1-bgp]router-id 1.1.1.1
[r1-bgp]peer 12.0.0.2 as-number 200
[r1-bgp]peer 13.0.0.3 as-number 200

[r2]bgp 200
[r2-bgp]router-id 2.2.2.2
[r2-bgp]peer 12.0.0.1 as-number 100
[r2-bgp]peer 3.3.3.3 as-number 200
[r2-bgp]peer 4.4.4.4 as-number 200
[r2-bgp]peer 3.3.3.3 connect-interface LoopBack 0
[r2-bgp]peer 4.4.4.4 connect-interface LoopBack 0

[r3]bgp 200
[r3-bgp]router-id 3.3.3.3
[r3-bgp]peer 13.0.0.1 as-number 100
[r3-bgp]peer 36.0.0.6 as-number 300
[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 LoopBack 0
[r3-bgp]peer 4.4.4.4 connect-interface LoopBack 0

[r4]bgp 200
[r4-bgp]router-id 4.4.4.4
[r4-bgp]peer 45.0.0.5 as-number 300
[r4-bgp]peer 47.0.0.7 as-number 400
[r4-bgp]peer 3.3.3.3 as-number 200
[r4-bgp]peer 2.2.2.2 as-number 200
[r4-bgp]peer 3.3.3.3 connect-interface LoopBack 0
[r4-bgp]peer 2.2.2.2 connect-interface LoopBack 0

[r5]bgp 300
[r5-bgp]router-id 5.5.5.5
[r5-bgp]peer 45.0.0.4 as-number 200

[r6]bgp 300
[r6-bgp]router-id 6.6.6.6
[r6-bgp]peer 36.0.0.1 as-number 300
[r6-bgp]peer 67.0.0.7 as-number 400
[r6-bgp]peer 69.0.0.9 as-number 500

[r7]bgp 400
[r7-bgp]router-id 7.7.7.7
[r7-bgp]peer 47.0.0.4 as-number 400
[r7-bgp]peer 67.0.0.6 as-number 300
[r7-bgp]peer 78.0.0.8 as-number 500
[r7-bgp]peer 107.0.0.10 as-number 500

[r8]bgp 500
[r8-bgp]router-id 8.8.8.8
[r5-bgp]peer 78.0.0.7 as-number 400

[r9]bgp 500
[r9-bgp]router-id 9.9.9.9
[r9-bgp]peer 69.0.0.6 as-number 300
[r9-bgp]peer 10.10.10.10 as-number 500
[r9-bgp]peer 10.10.10.10 connect-interface LoopBack 0

[r10]bgp 500
[r10-bgp]router-id 10.10.10.10
[r10-bgp]peer 107.0.0.7 as-number 400
[r10-bgp]peer 9.9.9.9 as-number 500
[r10-bgp]peer 9.9.9.9 connect-interface LoopBack 0

4.路由发布

AS内部所有运行BGP协议的设备，都需要通过BGP发布AS内部的路由信息

复制代码

[r1]bgp 100
[r1-bgp]network 192.168.1.0 24

[r2]bgp 200
[r2-bgp]network 192.168.2.0 24
[r2-bgp]network 192.168.3.0 24
[r2-bgp]network 192.168.4.0 24

[r3]ip ip-prefix aa permit 192.168.0.0 16 greater-equal 24 less-equal 24 --- 抓流量
[r3]route-policy aa permit node 10 --- 创建一个名称为aa的route-policy，节点编号为10，动作
允许
[r3-route-policy]if-match ip-prefix aa --- 做策略
[r3]bgp 200
[r3-bgp]import-route ospf 1 route-policy aa

[r4]ip ip-prefix aa permit 192.168.0.0 16 greater-equal 24 less-equal 24
[r4]route-policy aa permit node 10
[r4-route-policy]if-match ip-prefix aa
[r4]bgp 200
[r4-bgp]import-route ospf 1 route-policy aa

[r5]bgp 300
[r1-bgp]network 192.168.5.0 24

[r6]bgp 300
[r6-bgp]network 192.168.6.0 24
 
[r7]bgp 400
[r7-bgp]network 192.168.7.0 24

[r8]bgp 500
[r8-bgp]network 192.168.8.0 24

[r9]ip ip-prefix aa permit 192.168.0.0 16 greater-equal 24 less-equal 24
[r9]route-policy aa permit node 10
[r9-route-policy]if-match ip-prefix aa
[r9]bgp 500
[r9-bgp]import-route ospf 1 route-policy aa

[r10]ip ip-prefix aa permit 192.168.0.0 16 greater-equal 24 less-equal 24
[r10]route-policy aa permit node 10
[r10-route-policy]if-match ip-prefix aa
[r10]bgp 500
[r10-bgp]import-route ospf 1 route-policy aa

5.EBGP的水平分割机制
如果因为 AS_Path 属性导致路由无法学习，在保证没有环路的前提下，可以使用如下命令消除对
AS_Path 属性的检测

$r10-bgp$ peer 107.0.0.7 allow-as-loop 2
R10 从 107.0.0.7 这个邻居学习路由信息时，允许 AS 号重复 1 次。

复制代码

[r10]bgp 100
[r10-bgp]peer 107.0.0.7 allow-as-loop 2
[r10]bgp 500
[r10-bgp]peer 9.9.9.9 allow-as-loop 2
[r10-bgp]peer 9.9.9.9 next-hop-local --- 将nexthop属性修改为本地

[r9]bgp 500
[r9-bgp]peer 69.0.0.6 allow-as-loop 2
[r9-bgp]peer 10.10.10.10 next-hop-local

[r2]bgp 200
[r2-bgp]peer 3.3.3.3 next-hop-local
[r2-bgp]peer 4.4.4.4 next-hop-local

[r3]bgp 200
[r3-bgp]peer 2.2.2.2 next-hop-local
[r3-bgp]peer 4.4.4.4 next-hop-local

[r4]bgp 200
[r4-bgp]peer 2.2.2.2 next-hop-local
[r4-bgp]peer 3.3.3.3 next-hop-local

[r5]bgp 300
[r5-bgp]peer 45.0.0.4 allow-as-loop 2

[r6]bgp 300
[r6-bgp]peer 36.0.0.3 allow-as-loop 2
[r6-bgp]peer 67.0.0.7 allow-as-loop 2
[r6-bgp]peer 69.0.0.9 allow-as-loop 2

$r2-bgp$ peer 3.3.3.3 next-hop-local
--- R2 给 3.3.3.3 传递路由信息时，将 nexthop 属性修改为本地，即修改为 2.2.2.2
这条命令用在ebgp和ibgp之间