1.R2-R7每台路由器均存在一个环回接口用于建立邻居;同时还存在一个环回来代替连接用户接口;最终这些连接用户的接口网络需要可以和R1/8的环回通讯。
2.AS2网段地址172.16.0.0/16, 减少路由条目数量。
1.IP地址规划
172.16.0.0/16
172.16.0.0/24—骨干链路172.16.0.0/30
172.16.1.0/24—建立邻居的环回,172.16.1.1/24、172.16.1.2/24、172.16.1.3/24等
172.16.2.0/24
172.16.3.0/24
172.16.4.0/24
172.16.5.0/24
172.16.6.0/24
172.16.7.0/24
剩下这6个网段作为R2-7的业务网段。
2.配置IP地址
R1:
[R1]int g0/0/0 [R1-GigabitEthernet0/0/0]ip address 12.1.1.1 24 [R1]int LoopBack 0 [R1-LoopBack0]ip address 1.1.1.1 32
R2:
[R2]int g0/0/0 [R2-GigabitEthernet0/0/0]ip address 12.1.1.1 24 [R2-GigabitEthernet0/0/0]int g0/0/1 [R2-GigabitEthernet0/0/1]ip address 172.16.0.1 30 [R2-GigabitEthernet0/0/0]int g0/0/2 [R2-GigabitEthernet0/0/2]ip address 172.16.0.9 30 [R2]int LoopBack 0 [R2-LoopBack0]ip address 172.16.1.2 32
R3:
[R3]int g0/0/0 [R3-GigabitEthernet0/0/0]ip address 172.16.0.2 30 [R3-GigabitEthernet0/0/0]int g0/0/1 [R3-GigabitEthernet0/0/1]ip address 172.16.0.5 30 [R3]int LoopBack 0 [R3-LoopBack0]ip address 172.16.1.3 32
R4:
[R4]int g0/0/0 [R4-GigabitEthernet0/0/0]ip address 172.16.0.6 30 [R4-GigabitEthernet0/0/0]int g0/0/1 [R4-GigabitEthernet0/0/1]ip address 172.16.0.21 30 [R4]int LoopBack 0 [R4-LoopBack0]ip address 172.16.1.3 32
R5:
[R5]int g0/0/0 [R5-GigabitEthernet0/0/0]ip address 172.16.0.13 30 [R5-GigabitEthernet0/0/0]int g0/0/1 [R5-GigabitEthernet0/0/1]ip address 172.16.0.10 30 [R5]int LoopBack 0 [R5-LoopBack0]ip address 172.16.1.5 32
R6:
[R6]int g0/0/0 [R6-GigabitEthernet0/0/0]ip address 172.16.0.14 30 [R6-GigabitEthernet0/0/0]int g0/0/1 [R6-GigabitEthernet0/0/1]ip address 172.16.0.17 30 [R6]int LoopBack 0 [R6-LoopBack0]ip address 172.16.1.6 32
R7:
[R7]int g0/0/0 [R7-GigabitEthernet0/0/0]ip address 172.16.0.22 30 [R7-GigabitEthernet0/0/0]int g0/0/1 [R7-GigabitEthernet0/0/1]ip address 172.16.0.18 30 [R7-GigabitEthernet0/0/0]int g0/0/2 [R7-GigabitEthernet0/0/1]ip address 78.1.1.1.1 24 [R7]int LoopBack 0 [R7-LoopBack0]ip address 172.16.1.7 32
R8:
[R7]int g0/0/0 [R7-GigabitEthernet0/0/0]ip address 78.1.1.2 24 [R7]int LoopBack 0 [R7-LoopBack0]ip address 8.8.8.8 32
2.将AS2中的IGP协议启动并宣告
R2:
[R2]ospf 1 [R2-ospf-1]area 0 [R2-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255
R3:
[R3]ospf 1 [R3-ospf-1]area 0 [R3-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255
R4:
[R4]ospf 1 [R4-ospf-1]area 0 [R4-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255
R5:
[R5]ospf 1 [R5-ospf-1]area 0 [R5-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255
R6:
[R6]ospf 1 [R6-ospf-1]area 0 [R6-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255
R7:
[R7]ospf 1 [R7-ospf-1]area 0 [R7-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255
4.启动BGP协议并建立邻居关系
R1:
[R1]bgp 1 [R1-bgp]router-id 1.1.1.1 [R1-bgp]peer 12.1.1.2 as-number 2
R2:
[R2]bgp 64512 [R2-bgp]router-id 172.16.1.2 [R2-bgp]confederation id 2 [R2-bgp]peer 12.1.1.1 as-number 1 [R2-bgp]peer 172.16.1.3 as-number 64512 [R2-bgp]peer 172.16.1.3 connect-interface LoopBack 0 [R2-bgp]confederation peer-as 64513 [R2-bgp]peer 172.16.1.5 as-number 64513 [R2-bgp]peer 172.16.1.5 ebgp-max-hop 2 [R2-bgp]peer 172.16.1.5 connect-interface LoopBack 0
R3:
[R3]bgp 64512 [R3-bgp]router-id 172.16.1.3 [R3-bgp]peer 172.16.1.2 as-number 64512 [R3-bgp]peer 172.16.1.2 connect-interface LoopBack 0 [R3-bgp]peer 172.16.1.4 as-number 64512 [R3-bgp]peer 172.16.1.4 connect-interface LoopBack 0
R4:
[R4]bgp 64512 [R4-bgp]router-id 172.16.1.4 [R4-bgp]confederation id 2 [R4-bgp]peer 172.16.1.3 as-number 64512 [R4-bgp]peer 172.16.1.3 connect-interface LoopBack 0 [R4-bgp]confederation peer-as 64513 [R4-bgp]peer 172.16.1.7 as-number 64513 [R4-bgp]peer 172.16.1.7 ebgp-max-hop 2 [R4-bgp]peer 172.16.1.7 connect-interface LoopBack 0
R5:
[R5]bgp 64513 [R5-bgp]router-id 172.16.1.5 [R5-bgp]confederation id 2 [R5-bgp]confederation peer-as 64512 [R5-bgp]peer 172.16.1.2 as-number 64512 [R5-bgp]peer 172.16.1.2 ebgp-max-hop 2 [R5-bgp]peer 172.16.1.2 connect-interface LoopBack 0 [R5-bgp]peer 172.16.1.6 as-number 64513 [R5-bgp]peer 172.16.1.6 connect-interface LoopBack 0
R6:
[R6]bgp 64513 [R6-bgp]router-id 172.16.1.6 [R6-bgp]confederation id 2 [R6-bgp]peer 172.16.1.5 as-number 64513 [R6-bgp]peer 172.16.1.5 connect-interface LoopBack 0 [R6-bgp]peer 172.16.1.7 as-number 64513 [R6-bgp]peer 172.16.1.7 connect-interface LoopBack 0
R7:
[R7]bgp 64513 [R7-bgp]router-id 172.16.1.7 [R7-bgp]peer 172.16.1.6 as-number 64513 [R7-bgp]peer 172.16.1.6 connect-interface LoopBack 0 [R7-bgp]confederation peer-as 64512 [R7-bgp]peer 172.16.1.4 as-number 64512 [R7-bgp]peer 172.16.1.4 ebgp-max-hop 2 [R7-bgp]peer 172.16.1.4 connect-interface LoopBack 0 [R7-bgp]peer 78.1.1.8 as-number 3
R8:[R8]bgp 3 [R8-bgp]router-id 8.8.8.8 [R8-bgp]peer 78.1.1.7 as-number 2
5.宣告业务网段
R1:
[R1-bgp]network 10.1.1.0 24
在R2上查看BGP表发现学到R1的业务网段是优的,但是R3和R5上学到的却是不优的,所以需要修改下一跳IP地址;
R2:
[R2-bgp]peer 172.16.1.3 next-hop-local [R2-bgp]peer 172.16.1.5 next-hop-local
在R3和R6上写反射器
R3:
[R3-bgp]peer 172.16.1.4 reflect-client
R6:
[R6-bgp]peer 172.16.1.7 reflect-client
宣告R8的业务网段,并在R7上修改下一跳
R8:
[R8-bgp]network 10.1.8.0 24
R7:
[R7-bgp]peer 172.16.1.4 next-hop-local [R7-bgp]peer 172.16.1.6 next-hop-local
在R2,R7上宣告聚合后的用户接口网络
R2:
[R2]ip route-static 172.16.0.0 21 NULL 0 [R2]bgp 64512 [R2-bgp]network 172.16.0.0 21
R7:
[R7]ip route-static 172.16.0.0 21 NULL 0 [R7]bgp 64513 [R7-bgp]network 172.16.0.0 21
四.实验结果