bgp优化实验-优快云博客

本文链接：https://blog.youkuaiyun.com/YHSdaxuexi/article/details/148067819

需求

PreVal 策略：在 AR4 上配置 PreVal 策略，让其去往 192.168.10.0/24 网段时优先选择经 AR2 的路径，需设置相关属性使该路径在选路时更优。

AS_Path 策略：在 AR4 上运用 AS_Path 策略，使其去往 192.168.11.0/24 网段走 AR3 路径，可能通过修改 AS_Path 长度或添加特定 AS 号，影响选路。

MED 策略：配置 MED 策略控制 AR4 到 192.168.12.0/24 路由的路径，MED 用于向外部 AS 建议进入本 AS 时的最佳入口路径，需合理设置 MED 值引导流量。

Local Preference 策略 - 1：在 AS 123 内配置，让 AR1 去往 192.168.1.0/24 网段时优先走 AR2 路径，Local Preference 在 AS 内部影响选路，值越高越优先。

Local Preference 策略 - 2：在 AS 123 内配置，使 AR1 去往 192.168.2.0/24 网段时优先选 AR3 路径，同样是设置合适 Local Preference 值。

R1

R1]int l 0
[R1-LoopBack0]ip add 1.1.1.1 32
[R1-LoopBack0]int l 1
[R1-LoopBack1]ip add 192.168.100.1 24
[R1-LoopBack1]int g 0/0/0
[R1-GigabitEthernet0/0/0]ip add 12.0.0.2 24
[R1-GigabitEthernet0/0/0]int g 0/0/1
[R1-GigabitEthernet0/0/1]ip add 13.0.0.2 24
[R1-GigabitEthernet0/0/1]int g 0/0/2
[R1-GigabitEthernet0/0/2]ip add 15.0.0.1 24

R2

[R2]int l 0
[R2-LoopBack0]ip add 2.2.2.2 32
[R2-LoopBack0]int l 1
[R2-LoopBack1]ip add 192.168.20.1 24
[R2-LoopBack1]int g 0/0/0
[R2-GigabitEthernet0/0/0]ip add 24.0.0.2 24
[R2-GigabitEthernet0/0/0]int g 0/0/1
[R2-GigabitEthernet0/0/1]ip add 12.0.0.1 24

R3

[R3]int l 0
[R3-LoopBack0]ip add 3.3.3.3 32
[R3-LoopBack0]int l 1
[R3-LoopBack1]ip add 192.168.30.1 24
[R3-LoopBack1]int g 0/0/0
[R3-GigabitEthernet0/0/0]ip add 34.0.0.2 24
[R3-GigabitEthernet0/0/0]int g 0/0/1
[R3-GigabitEthernet0/0/1]ip add 13.0.0.1 24

R4

[R4]int l 0
[R4-LoopBack0]ip add 192.168.1.1 24
[R4-LoopBack0]int l 1
[R4-LoopBack1]ip add 192.168.2.1 24
[R4-LoopBack1]int l 2
[R4-LoopBack2]ip add 192.168.3.1 24
[R4-LoopBack2]int g 0/0/0
[R4-GigabitEthernet0/0/0]ip add 24.0.0.1 24
[R4-GigabitEthernet0/0/0]int g 0/0/1
[R4-GigabitEthernet0/0/1]ip add 34.0.0.1 24

R5

[R5]int l 0
[R5-LoopBack0]ip add 192.168.10.1 24
[R5-LoopBack0]int l 1
[R5-LoopBack1]ip add 192.168.11.1 24
[R5-LoopBack1]int l 2
[R5-LoopBack2]ip add 192.168.12.1 24
[R5-LoopBack2]int g 0/0/0
[R5-GigabitEthernet0/0/0]ip add 15.0.0.2 24

修改环回接口网络类型

[R1]int l 1
[R1-LoopBack1]ospf network-type broadcast

[R2]int l 1
[R2-LoopBack1]ospf network-type broadcast

[R3]int l 1
[R3-LoopBack1]ospf network-type broadcast

R1

[R1]ospf 1 rou 1.1.1.1
[R1-ospf-1]a 0
[R1-ospf-1-area-0.0.0.0]net 1.1.1.1 0.0.0.0
[R1-ospf-1-area-0.0.0.0]net 12.0.0.2 0.0.0.0
[R1-ospf-1-area-0.0.0.0]net 13.0.0.2 0.0.0.0
[R1-ospf-1-area-0.0.0.0]net 192.168.100.1 0.0.0.0

R2

[R2]ospf 1 rou 2.2.2.2
[R2-ospf-1]a 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 192.168.20.1 0.0.0.0
[R2-ospf-1-area-0.0.0.0]net 12.0.0.1 0.0.0.0

R3

[R3]ospf 1 rou 3.3.3.3
[R3-ospf-1]a 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 192.168.30.1 0.0.0.0
[R3-ospf-1-area-0.0.0.0]net 13.0.0.1 0.0.0.0

启动bgp配置

[R4]bgp 400
[R4-bgp]router-id 4.4.4.4
[R4-bgp]peer 24.0.0.2 as 123
[R4-bgp]peer 34.0.0.2 as 123

[R2]bgp 123
[R2-bgp]router-id 2.2.2.2
[R2-bgp]peer 24.0.0.1 as 400
[R2-bgp]peer 1.1.1.1 as 123
[R2-bgp]peer 1.1.1.1 con l0
[R2-bgp]peer 1.1.1.1 next-hop-local

[R3]bgp 123
[R3-bgp]router-id 3.3.3.3
[R3-bgp]peer 34.0.0.1 as 400
[R3-bgp]peer 1.1.1.1 as 123
[R3-bgp]peer 1.1.1.1 con l0
[R3-bgp]peer 1.1.1.1 next-hop-local

[R1]bgp 123
[R1-bgp]router-id 1.1.1.1
[R1-bgp]peer 2.2.2.2 as 123
[R1-bgp]peer 2.2.2.2 con l0
[R1-bgp]peer 2.2.2.2 next-hop-local
[R1-bgp]peer 3.3.3.3 as 123
[R1-bgp]peer 3.3.3.3 con l0
[R1-bgp]peer 3.3.3.3 next-hop-local
[R1-bgp]peer 15.0.0.2 as 500

[R5]bgp 500
[R5-bgp]router-id 5.5.5.5
[R5-bgp]peer 15.0.0.1 as 123

宣告环回接口

[R4]bgp 400
[R4-bgp]net 192.168.1.0 24
[R4-bgp]net 192.168.2.0 24
[R4-bgp]net 192.168.3.0 24

[R2]bgp 123
[R2-bgp]net 192.168.20.0 24

[R3]bgp 123
[R3-bgp]net 192.168.30.0 24

[R1]bgp 123
[R1-bgp]net 192.168.100.0 24

[R5]bgp 500
[R5-bgp]net 192.168.10.0 24
[R5-bgp]net 192.168.11.0 24
[R5-bgp]net 192.168.12.0 24

使用PreVa1策略，确保R4通过R2到达192.168.10.0/24

[R4]ip ip-prefix pv permit 192.168.10.0 24
[R4]route-policy pv permit node 10
[R4-route-policy]if-match ip-prefix pv
[R4-route-policy]apply preferred-value 100
[R4]route-policy pv permit node 100
[R4]bgp 400
[R4-bgp]peer 24.0.0.2 route-policy pv impor

使用AS_Path策略，确保R4通过R3到达192.168.11.0/24

[R4]ip ip-prefix ap permit 192.168.11.0 24
[R4]route-policy pv permit node 20
[R4-route-policy]if-match ip-prefix ap
[R4-route-policy]apply as-path 123 additive

配置MED策略，确保R4通过R3到达192.168.12.0/24

[R4]ip ip-prefix med permit 192.168.12.0 24
[R4]route-policy pv permit node 30
[R4-route-policy]if-match ip-prefix med
[R4-route-policy]apply cost 20

使用Local Preference策略，确保R1通过R2到达192.168.1.0/24

[R1]ip ip-prefix lp1 permit 192.168.1.0 24
[R1]route-policy lp1 permit node 10
[R1-route-policy]if-match ip-prefix lp1
[R1-route-policy]apply local-preference 200
[R1]route-policy lp1 permit node 100
Info: New Sequence of this List.
[R1]bgp 123
[R1-bgp]peer 2.2.2.2 route-policy lp1 import

使用Local Preference策略，确保R1通过R3到达192.168.2.0/24

[R1]ip ip-prefix lp2 permit 192.168.2.0 24
[R1]route-policy lp2 permit node 10
[R1-route-policy]if-match ip-prefix lp2
[R1-route-policy]apply local-preference 200
[R1]route-policy lp2 permit node 100
Info: New Sequence of this List.
[R1]bgp 123
[R1-bgp]peer 3.3.3.3 route-policy lp2 import