实验TOP：
实验配置：
【实验配置】：
100：bgp 100
network 100.100.100.100 255.255.255.255
network 200.200.200.200 255.255.255.255
undo synchronization
peer 14.14.14.2 as-number 200
group 200 external
peer 14.14.14.2 group 200
interface LoopBack100
ip address 100.100.100.100 255.255.255.25
interface LoopBack200
ip address 200.200.200.200 255.255.255.255
130：bgp 200
network 10.10.10.10 255.255.255.255
network 20.20.20.20 255.255.255.255
undo synchronization
peer 14.14.14.1 as-number 100
peer 34.34.34.1 as-number 300
group 100 external
peer 14.14.14.1 group 100
group 300 external
peer 34.34.34.1 group 300
interface LoopBack10
ip address 10.10.10.10 255.255.255.255
interface LoopBack20
ip address 20.20.20.20 255.255.255.255
120：bgp 300
undo synchronization
peer 34.34.34.2 as-number 200
group 200 external
peer 34.34.34.2 group 200
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第一种策略方法(Acl+拒绝模式);
130：acl number 2000
rule 10 permit source 100.100.100.100 0
rule 20 permit source 200.200.200.200 0
rule 30 deny
acl number 2001
rule 10 permit source 10.10.10.10 0
rule 20 permit source 20.20.20.20 0
rule 30 den
route-policy 1 deny node 0
if-match acl 2000
route-policy 1 permit node 1
if-match acl 2001
peer 34.34.34.1 route-policy 1 export
120: [R-3-bgp]dis bgp rou
BGP Local router ID is 192.168.1.120
Network NextHop MED LocPrf PrefVal Path/Ogn
*> 10.10.10.10/32 34.34.34.2 0 0 200i
*> 20.20.20.20/32 34.34.34.2 0 0 200i
第二种策略方法(as-path acl+拒绝模式);
120: ip as-path 1 permit _100$
ip as-path 1 deny .*
ip as-path 2 permit _200$
ip as-path 2 deny .*
route-policy 1 deny node 0
if-match as-path 1
route-policy 1 permit node 1
if-match as-path 2
bgp 300
peer 34.34.34.2 route-policy 1 import
120: [R-3-bgp]dis bgp rou
BGP Local router ID is 192.168.1.120
Network NextHop MED LocPrf PrefVal Path/Ogn
*> 10.10.10.10/32 34.34.34.2 0 0 200i
*> 20.20.20.20/32 34.34.34.2 0 0 200i
第三种策略方法(as-path+允许模式);
120: ip as-path 1 permit _200$
ip as-path 1 deny .*
route-policy 1 permit node 0
if-match as-path 1
peer 34.34.34.2 route-policy 1 import
120: [R-3]dis bgp rou
BGP Local router ID is 192.168.1.120
Network NextHop MED LocPrf PrefVal Path/Ogn
*> 10.10.10.10/32 34.34.34.2 0 0 200i
*> 20.20.20.20/32 34.34.34.2 0 0 200i