利用BGP虚拟下一跳技术实现IP骨干网流量负载均衡

I; 19三I阐血血弟一晦小一海172,16.16.im心，'和I72.II5JWI71.lfi.lfrj.3tll6.2S.2；3ir%,比-心，'3。VZ.ltK.O.lfJl172A6A2A171112.2/30监"8业倾SLGE,心只'3口1j.U.A'3!I(143.0.43：172,1633/311l?2.lh.34.+/J0SL1)173.1&2LU34)Area 1IH>Hl、始需螯以虚拟下一肱 吵曲;和其它自治城崖立 EIK；F邻居关系配置说明：【R1】interface Loopback0ip address 192.168.0.1 255.255.255.255interface Serial1/0no ship address 172.16.15.1 255.255.255.0interface Serial1/1no ship address 172.16.12.1 255.255.255.0interface Serial1/2no ship address 172.16.16.1 255.255.255.0 interface Serial1/3no ship address 172.16.13.1 255.255.255.0ip route 10.0.0.1 255.255.255.255 172.16.13.3【虚拟下一跳地址指向真正下一跳，并由本域内IGP(OSPF)路由引入，使本域内所有邻居都能学习到虚拟下一跳地址的路由，从 而使邻居从自己学习到的路由能最优化】ip route 192.168.0.3 255.255.255.255 172.16.13.3ip prefix-list ISP-B seq 5 permit 172.16.34.0/2【做前缀列表匹配需要改变下一跳的 前缀】route-map set-nexthop permit 10【做 route-map，改相应前缀下一跳性】match ip address prefix-list ISP-Bset ip next-hop 10.0.0.1route-map set-nexthop permit 20router ospf 1router-id 192.168.0.1no auto-costredistribute static metric 10 metric-type 1 subnets【引入静态路由，使域内所有IBGP邻居能学到虚拟下一跳地址，从面使邻居从自己学习到的路由能最优化】network172.16.12.00.0.0.255area0network172.16.15.00.0.0.255area0network172.16.16.00.0.0.255area0network192.168.0.00.0.0.255area0router bgp 100no synchronizationbgp router-id 192.168.0.1bgp log-neighbor-changesneighbor internal peer-groupneighbor internal remote-as 100neighbor internal update-source Loopback0neighbor internal route-map set-nexthop out【做出方向的 ruout-map 改变发向邻居路 由的下一跳】neighbor 192.168.0.2 peer-group internalneighbor 192.168.0.3 remote-as 200neighbor 192.168.0.3 ebgp-multihop 255neighbor 192.168.0.3 update-source Loopback0neighbor 192.168.0.3 soft-reconfiguration inboundneighbor 192.168.0.5 peer-group internalneighbor 192.168.0.6 peer-group internalno auto-summary【R2】 interface Loopback0ip address 192.168.0.2 255.255.255.255interface Serial1/0no ship address 172.16.26.2 255.255.255.0interface Serial1/1no ship address 172.16.12.2 255.255.255.0interface Serial1/2no ship address 172.16.25.2 255.255.255.0interface Serial1/3no ship address 172.16.24.2 255.255.255.0ip route 10.0.0.1 255.255.255.255 172.16.24.4【虚拟下一跳地址指向真正下一跳，并 由本域内IGP(OSPF)路由引入，使本域内所有邻居都能学习到虚拟下一跳地址的路由，从而 使邻居从自己学习到的路由能最优化】ip route 192.168.0.4 255.255.255.255 172.16.24.4ip prefix-list ISP-B seq 5 permit 172.16.34.0/2【做前缀列表匹配需要改变下一跳的 前缀】route-map set-nexthop permit 10【做 route-map，改相应前缀下一跳性】match ip address prefix-list ISP-Bset ip next-hop 10.0.0.1route-map set-nexthop permit 20router ospf 1router-id 192.168.0.2log-adjacency-changesno auto-costredistribute static metric 10 metric-type 1 subnets【引入静态路由，使域内所有IBGP邻居能学到虚拟下一跳地址，从面使邻居从自己学习到的路由能最优化】network 172.16.12.0 0.0.0.255 area 0network 172.16.25.0 0.0.0.255 area 0network 172.16.26.0 0.0.0.255 area 0network 192.168.0.0 0.0.0.255 area 0router bgp 100no synchronizationbgp router-id 192.168.0.2bgp log-neighbor-changesneighbor internal peer-groupneighbor internal remote-as 100neighbor internal update-source Loopback0neighbor internal route-map set-nexthop out【做出方向的 ruout-map 改变发向邻居路 由的下一跳】neighbor 192.168.0.1 peer-group internalneighbor 192.168.0.4 remote-as 200neighbor 192.168.0.4 ebgp-multihop 255neighbor 192.168.0.4 update-source Loopback0neighbor 192.168.0.5 peer-group internalneighbor 192.168.0.6 peer-group internalno auto-summary【R3】由于R3、R4域内没有其它IBGP邻居，下挂设备都运行IGP所以不需要以虚拟下一跳 的方式建立EBGP邻居，可以用正常的方式建立EBGP邻居即可 interface Loopback0ip address 192.168.0.3 255.255.255.255interface Serial1/0no ship address 172.16.34.3 255.255.255.0interface Serial1/3no ship address 172.16.13.3 255.255.255.0router ospf 1router-id 192.168.0.3log-adjacency-changesno auto-costnetwork 172.16.34.0 0.0.0.255 area 0network 192.168.0.0 0.0.0.255 area 0 router bgp 200no synchronizationbgp router-id 192.168.0.3bgp log-neighbor-changesnetwork 1.0.0.0network 172.16.34.0 mask 255.255.255.0neighbor 192.168.0.1 remote-as 100neighbor 192.168.0.1 ebgp-multihop 255neighbor 192.168.0.1 update-source Loopback0neighbor 192.168.0.1 soft-reconfiguration inboundneighbor 192.168.0.4 remote-as 200neighbor 192.168.0.4 update-source Loopback0no auto-summaryip route 0.0.0.0 0.0.0.0 172.16.13.1ip route 1.0.0.0 255.0.0.0 Null0ip route 192.168.0.1 255.255.255.255 172.16.13.1【R4】由于R3、R4域内没有其它IBGP邻居，下挂设备都运行IGP所以不需要以虚拟下一跳 的方式建立EBGP邻居，可以用正常的方式建立EBGP邻居即可 interface Loopback0ip address 192.168.0.4 255.255.255.255interface Serial1/0no ship address 172.16.34.4 255.255.255.0serial restart-delay 0interface Serial1/3no ship address 172.16.24.4 255.255.255.0serial restart-delay 0router ospf 1router-id 192.168.0.4log-adjacency-changesno auto-costnetwork 172.16.34.0 0.0.0.255 area 0network 192.168.0.0 0.0.0.255 area 0 router bgp 200no synchronizationbgp router-id 192.168.0.4 bgp log-neighbor-changes network 1.0.0.0network 172.16.34.0 mask 255.255.255.0neighbor 192.168.0.2 remote-as 100neighbor 192.168.0.2 ebgp-multihop 255neighbor 192.168.0.2 update-source Loopback0neighbor 192.168.0.3 remote-as 200neighbor 192.168.0.3 update-source Loopback0 no auto-summaryip route 0.0.0.0 0.0.0.0 172.16.24.2ip route 1.0.0.0 255.0.0.0 Null0ip route 192.168.0.2 255.255.255.255 172.16.24.2【R5】R5、R6属于域内设备不建立EBGP邻居关系，也只要以正常方式与域内其它设备建立 IBGP邻居关系即可 interface Loopback0ip address 192.168.0.5 255.255.255.255interface Serial1/0no ship address 172.16.15.5 255.255.255.0interface Serial1/1no ship address 172.16.56.5 255.255.255.0interface Serial1/2no ship address 172.16.25.5 255.255.255.0router ospf 1router-id 192.168.0.5log-adjacency-changesno auto-costnetwork 172.16.0.0 0.0.255.255 area 0network 192.168.0.0 0.0.0.255 area 0router bgp 100no synchronizationbgp router-id 192.168.0.5bgp log-neighbor-changesneighbor internal peer-groupneighbor internal remote-as 100neighbor internal update-source Loopback0neighbor 192.168.0.1 peer-group internalneighbor 192.168.0.2 peer-group internalneighbor 192.168.0.6 peer-group internal no auto-summary【R6】R5、R6属于域内设备不建立EBGP邻居关系，也只要以正常方式与域内其它设备建立 IBGP邻居关系即可interface Loopback0ip address 192.168.0.6 255.255.255.255interface Serial1/0no ship address 172.16.26.6 255.255.255.0interface Serial1/1no ship address 172.16.56.6 255.255.255.0interface Serial1/2no ship address 172.16.16.6 255.255.255.0router ospf 1router-id 192.168.0.6 log-adjacency-changes no auto-costnetwork 172.16.0.0 0.0.255.255 area 0network 192.168.0.0 0.0.0.255 area 0router bgp 100no synchronizationbgp router-id 192.168.0.6bgp log-neighbor-changesneighbor internal peer-groupneighbor internal remote-as 100neighbor internal update-source Loopback0neighbor 192.168.0.1 peer-group internalneighbor 192.168.0.2 peer-group internalneighbor 192.168.0.5 peer-group internalno auto-summary