如下图示：
R1: interface Loopback0 ip address 1.1.1.1 255.255.255.255 interface Loopback11 ip address 11.11.11.1 255.255.255.0 interface Loopback101 ip address 101.1.1.1 255.255.255.0 interface FastEthernet0/0 ip address 12.1.1.1 255.255.255.0 no sh interface FastEthernet0/1 ip address 13.1.1.1 255.255.255.0 no sh router ospf 1 network 1.1.1.1 0.0.0.0 area 0 network 12.1.1.0 0.0.0.255 area 0 network 13.1.1.0 0.0.0.255 area 0 router bgp 1 bgp router-id 1.1.1.1 network 11.11.11.0 mask 255.255.255.0 network 101.1.1.0 mask 255.255.255.0 neighbor 2.2.2.2 remote-as 1 neighbor 2.2.2.2 update-source Loopback0 neighbor 3.3.3.3 remote-as 1 neighbor 3.3.3.3 update-source Loopback0 R2: interface Loopback0 ip address 2.2.2.2 255.255.255.255 interface Loopback22 ip address 22.22.22.2 255.255.255.0 interface FastEthernet0/0 ip address 12.1.1.2 255.255.255.0 no sh interface FastEthernet0/1 ip address 24.1.1.2 255.255.255.0 no sh router ospf 1 network 2.2.2.2 0.0.0.0 area 0 network 12.1.1.0 0.0.0.255 area 0 network 24.1.1.0 0.0.0.255 area 0 router bgp 1 bgp router-id 2.2.2.2 network 22.22.22.0 mask 255.255.255.0 neighbor 1.1.1.1 remote-as 1 neighbor 1.1.1.1 update-source Loopback0 neighbor 4.4.4.4 remote-as 4 neighbor 4.4.4.4 ebgp-multihop 255 neighbor 4.4.4.4 update-source Loopback0 R3: interface Loopback0 ip address 3.3.3.3 255.255.255.255 interface Loopback33 ip address 33.33.33.3 255.255.255.0 interface FastEthernet0/0 ip address 34.1.1.3 255.255.255.0 no sh interface FastEthernet0/1 ip address 13.1.1.3 255.255.255.0 no sh router ospf 1 network 3.3.3.3 0.0.0.0 area 0 network 13.1.1.0 0.0.0.255 area 0 network 34.1.1.0 0.0.0.255 area 0 router bgp 1 bgp router-id 3.3.3.3 network 33.33.33.0 mask 255.255.255.0 neighbor 1.1.1.1 remote-as 1 neighbor 1.1.1.1 update-source Loopback0 neighbor 4.4.4.4 remote-as 4 neighbor 4.4.4.4 ebgp-multihop 255 neighbor 4.4.4.4 update-source Loopback0 R4: interface Loopback0 ip address 4.4.4.4 255.255.255.255 interface Loopback44 ip address 44.44.44.4 255.255.255.0 interface FastEthernet0/0 ip address 34.1.1.4 255.255.255.0 no sh interface FastEthernet0/1 ip address 24.1.1.4 255.255.255.0 no sh interface FastEthernet1/0 ip address 45.1.1.4 255.255.255.0 no sh interface FastEthernet1/1 ip address 46.1.1.4 255.255.255.0 no sh router ospf 1 network 4.4.4.4 0.0.0.0 area 0 network 24.1.1.0 0.0.0.255 area 0 network 34.1.1.0 0.0.0.255 area 0 network 45.1.1.0 0.0.0.255 area 0 network 46.1.1.0 0.0.0.255 area 0 router bgp 4 bgp router-id 4.4.4.4 network 44.44.44.0 mask 255.255.255.0 //aggregate-address 101.1.0.0 255.255.252.0 as-set summary-only //抑制全部的101.1.0.0/22明细路由，只发汇总路由。（在此实验，这一条命令是多余的。） neighbor 2.2.2.2 remote-as 1 neighbor 2.2.2.2 ebgp-multihop 255 neighbor 2.2.2.2 update-source Loopback0 neighbor 3.3.3.3 remote-as 1 neighbor 3.3.3.3 ebgp-multihop 255 neighbor 3.3.3.3 update-source Loopback0 neighbor 5.5.5.5 remote-as 5 neighbor 5.5.5.5 ebgp-multihop 255 neighbor 5.5.5.5 update-source Loopback0 neighbor 6.6.6.6 remote-as 6 neighbor 6.6.6.6 ebgp-multihop 255 neighbor 6.6.6.6 update-source Loopback0 access-list 1 permit 101.1.1.0 //以下五行命令是抑制101.1.1.0这个网段不予通告路由。 route-map apple permit 10 match ip address 1 router bgp 4 aggregate-address 101.1.0.0 255.255.252.0 as-set suppress-map apple R5: interface Loopback0 ip address 5.5.5.5 255.255.255.255 interface Loopback55 ip address 55.55.55.5 255.255.255.0 interface FastEthernet1/0 ip address 45.1.1.5 255.255.255.0 no sh router ospf 1 network 5.5.5.5 0.0.0.0 area 0 network 45.1.1.0 0.0.0.255 area 0 router bgp 5 bgp router-id 5.5.5.5 network 55.55.55.0 mask 255.255.255.0 neighbor 4.4.4.4 remote-as 4 neighbor 4.4.4.4 ebgp-multihop 255 neighbor 4.4.4.4 update-source Loopback0 R6: interface Loopback0 ip address 6.6.6.6 255.255.255.255 interface Loopback66 ip address 66.66.66.6 255.255.255.0 interface Loopback101 ip address 101.1.3.6 255.255.255.0 secondary ip address 101.1.2.6 255.255.255.0 interface FastEthernet1/1 ip address 46.1.1.6 255.255.255.0 no sh router ospf 1 network 6.6.6.6 0.0.0.0 area 0 network 46.1.1.0 0.0.0.255 area 0 router bgp 6 bgp router-id 6.6.6.6 network 66.66.66.0 mask 255.255.255.0 network 101.1.2.0 mask 255.255.255.0 network 101.1.3.0 mask 255.255.255.0 neighbor 4.4.4.4 remote-as 4 neighbor 4.4.4.4 ebgp-multihop 255 neighbor 4.4.4.4 update-source Loopback0 R5(config-router)#do show ip bgp BGP table version is 32, local router ID is 5.5.5.5 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 11.11.11.0/24 4.4.4.4 0 4 1 i *> 22.22.22.0/24 4.4.4.4 0 4 1 i *> 33.33.33.0/24 4.4.4.4 0 4 1 i *> 44.44.44.0/24 4.4.4.4 0 0 4 i *> 55.55.55.0/24 0.0.0.0 0 32768 i *> 66.66.66.0/24 4.4.4.4 0 4 6 i *> 101.1.0.0/22 4.4.4.4 0 0 4 {1,6} i *> 101.1.2.0/24 4.4.4.4 0 4 6 i *> 101.1.3.0/24 4.4.4.4 0 4 6 i R1(config-router)#do show ip bgp BGP table version is 52, local router ID is 1.1.1.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 11.11.11.0/24 0.0.0.0 0 32768 i *>i22.22.22.0/24 2.2.2.2 0 100 0 i *>i33.33.33.0/24 3.3.3.3 0 100 0 i * i44.44.44.0/24 4.4.4.4 0 100 0 4 i *>i 4.4.4.4 0 100 0 4 i * i55.55.55.0/24 4.4.4.4 0 100 0 4 5 i *>i 4.4.4.4 0 100 0 4 5 i * i66.66.66.0/24 4.4.4.4 0 100 0 4 6 i *>i 4.4.4.4 0 100 0 4 6 i *> 101.1.1.0/24 0.0.0.0 0 32768 i * i101.1.2.0/24 4.4.4.4 0 100 0 4 6 i *>i 4.4.4.4 0 100 0 4 6 i * i101.1.3.0/24 4.4.4.4 0 100 0 4 6 i *>i 4.4.4.4 0 100 0 4 6 i R1(config-router)#do ping 101.1.2.6 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 101.1.2.6, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 44/64/112 ms
增加语句： R1: router bgp 1 neighbor 3.3.3.3 route-reflector-client //这两句必须加，否R2和R3不知道对方的存在。 neighbor 2.2.2.2 route-reflector-client