BGP大型企业网工程案例一《来源于互联网》

BGP大型企业网工程案例一
实验需求分析





某公司,总部在北京,在全国每个省都设有分公司（本实验模拟出两个省网）。现在要求各省的分公司能与总公司实现通信。公司的业务主要分为办公和生产两种。要求高质量的传输，因此建议将网络数据流量运行在两个平面上，一个生产平面，以及一个办公平面。生产平面在左边，办公平面在右边。要求严格控制。考虑到此公司的规模较大，将网络分为多个自治系统，每个省占一个，其中总部单独划出一个，进行全国的数据汇总,为此网络的骨干核心网络。每个自治系统间靠 BGP传递路由,自治系统内运行 OSPF。(因为是模拟器实验，所以有关广域网的技术就不做了，这里主是要做 BGP的组网)

实验组网需求：

实验拓扑如上图所示.其中 BGP AS 65000为全国骨干网,下面的两个省网从左到右分别为湖北和湖南。全国骨干网内部运行 OSPF，以及 BGP。R1和 R2为同簇双 RR，分别与所有省连接点路由器建立 RRC关系．数据中心运行 OSPF区域 1,在 RT1和 RT2发布汇总路由到区域

0.在 RT1、RT2上，发布全国骨干网汇总的链路及网管路由，及发布数据中心汇总的生产、办公、链路及网管的路由到 BGP中。

AS65001为湖北省网，RT9、RT10为省网出口路由器，运行 BGP，发布湖北省省网汇总的生产、办公、链路及网管的路由，并使用 EBGP上联全国骨干网湖北省节点 RT3、RT4；RT9、RT10向省网发布 OSPF缺省路由。

AS65002为湖南省网，RT13、RT14为省网出口路由器，运行 BGP，发布湖南省省网汇总的生产、办公、链路及网管的路由，并使用 EBGP上联全国骨干网湖南省节点 RT5、RT6； RT13、RT14向省网发布 OSPF缺省路由。

数据中心、湖北、湖南省网中的核心交换机运行 HSRP/VRRP，其中生产业务的主网关在左边(编号为奇数的设备)，办公业务的网关在右边(编号为偶数的设备)。整网使用路由策略进行业务分流；生产业务主路径走左边，办公业务主路径走右边。

OSPF配置规范：在任何不需要形成 OSPF邻居的接口上，配置 OSPF被动接口，配置点对点以太网的 OSPF网络类型为点对点，以加快收敛速度；各区域必须依据 IP地址规划做好路由汇总。

BGP配置要求：no synchronization;no auto-summary;使用 loopback0建立 IBGP邻居；IBGP邻居上配置 next-hop-self。WAN链路都是 8Mbps，平面间链路 OSPF COST都修改为 400,网络类型为点对点。

IP地址规划：

本网采用先业务后地区分配方法进行 IP地址规划因为是全国性的网络我们使用 10.0.0.0/8地址段进行分配，这里的业务只有生产业务和办公业务再加上互联链路及网管，只需借 2位就够用，全国共有 30多个省，我们分配 6位为地区位，64个足够用的。

10.业务位（2位）地区位（6位）.子业务位（8位）.子网位主机位

各地区 IP地址段









IP地址分配表





配置步骤：全国骨干网调测

1 全国骨干网基本连通性调测：RT1、RT2、RT3、RT4、RT5、RT6的基本信息、链路、IGP配置及测试。

2 OSPF配置配置接口 bandwith与物理带宽一致（全国骨干网的广域网链路都是 8Mbps）；调整平面间链路的 OSPF Cost为 400；RT1－RT2、RT3－RT4、RT5－RT6；在各省节点路由器（RT3、RT4、RT5、RT6）上，network边界网段至 OSPF，

并配置被动接口。

一.各链路基本配置及调测（略）二.各区域 IGP调测

骨干网及数据中心 IGP调测：

RT1：

router ospf 1

router-id 10.0.0.1

area 1 range 10.1.0.0 255.255.0.0

area 1 range 10.65.0.0 255.255.0.0//为区域 1路由汇总

area 1 range 10.129.0.0 255.255.0.0

network 10.0.0.1 0.0.0.0 area 0

network 10.0.1.0 0.0.0.3 area 0

network 10.0.1.4 0.0.0.3 area 0

network 10.0.1.20 0.0.0.3 area 0

network 10.1.1.0 0.0.0.3 area 1

default-information originate always metric 1000 //下发缺省路由

int f1/0

ip ospf network point-to-point//修改网络类型为点对点平面间开销为 400

ip ospf cost 400

int f2/0

ip ospf network point-to-point

RT2：

router ospf 1

router-id 10.0.0.2

area 1 range 10.1.0.0 255.255.0.0

area 1 range 10.65.0.0 255.255.0.0//为区域 1路由汇总

area 1 range 10.129.0.0 255.255.0.0

network 10.0.0.2 0.0.0.0 area 0

network 10.0.1.0 0.0.0.3 area 0

network 10.0.1.8 0.0.0.3 area 0

network 10.0.1.24 0.0.0.3 area 0

network 10.1.1.4 0.0.0.3 area 1 default-information originate always metric 1000 //下发缺省路由 int f1/0 ip ospf network point-to-point//修改网络类型为点对点平面间开销为 400 ip ospf cost 400 int f2/0 ip ospf network point-to-point

SW15： router ospf 1

router-id 10.1.0.1

passive-interface default

no passive-interface f1/0

no passive-interface vlan 901

network 10.1.0.1 0.0.0.0 area 1

network 10.1.1.0 0.0.0.3 area 1

network 10.1.1.8 0.0.0.3 area 1

network 10.65.1.0 0.0.0.255 area 1

network 10.129.1.0 0.0.0.255 area 1

int f1/0

ip ospf network point-to-point

int vlan 901

ip ospf network point-to-point//修改网络类型为点对点平面间开销为 400

ip ospf cost 400

SW16： router ospf 1

router-id 10.1.0.2

passive-interface default

no passive-interface f1/0

no passive-interface vlan 901

network 10.1.0.2 0.0.0.0 area 1

network 10.1.1.4 0.0.0.3 area 1

network 10.1.1.8 0.0.0.3 area 1

network 10.65.1.0 0.0.0.255 area 1

network 10.129.1.0 0.0.0.255 area 1

int f1/0

ip ospf network point-to-point

int vlan 901

ip ospf network point-to-point//修改网络类型为点对点平面间开销为 400

ip ospf cost 400 RT3: router ospf 1

router-id 10.0.0.3

redistribute connected metric 1000 metric-type 1 subnets

passive-interface FastEthernet2/0//不能与其它 AS形成 OSPF邻居

network 10.0.0.3 0.0.0.0 area 0

network 10.0.1.4 0.0.0.3 area 0

network 10.0.1.12 0.0.0.3 area 0RT4： router ospf 1

router-id 10.0.0.4

redistribute connected metric 1000 metric-type 1 subnets //重分布直连

passive-interface FastEthernet2/0

network 10.0.0.4 0.0.0.0 area 0

network 10.0.1.8 0.0.0.3 area 0

network 10.0.1.12 0.0.0.3 area 0 RT5: router ospf 1

router-id 10.0.0.5

redistribute connected metric 1000 metric-type 1 subnets

passive-interface FastEthernet2/0

network 10.0.0.5 0.0.0.0 area 0

network 10.0.1.20 0.0.0.3 area 0

network 10.0.1.28 0.0.0.3 area 0RT6： router ospf 1

router-id 10.0.0.6

redistribute connected metric 1000 metric-type 1 subnets

passive-interface FastEthernet2/0

network 10.0.0.6 0.0.0.0 area 0

network 10.0.1.24 0.0.0.3 area 0

network 10.0.1.28 0.0.0.3 area 0湖北网 IGP调测：RT9： router ospf 1

router-id 10.3.0.1

redistribute connected metric 1000 metric-type 1 subnets

passive-interface FastEthernet2/0

network 10.3.0.1 0.0.0.0 area 0

network 10.3.1.0 0.0.0.3 area 0

network 10.3.1.4 0.0.0.3 area 0

default-information originate always metric 3000 metric-type 1

int f3/0

ip ospf network point-to-point

int f1/0

ip ospf network point-to-point

ip ospf cost 400 RT10：

router ospf 1 router-id 10.3.0.2 redistribute connected metric 1000 metric-type 1 subnets passive-interface FastEthernet2/0 network 10.3.0.2 0.0.0.0 area 0 network 10.3.1.0 0.0.0.3 area 0 network 10.3.1.8 0.0.0.3 area 0 default-information originate always metric 3000 metric-type 1 int f3/0 ip ospf network point-to-point int f1/0 ip ospf network point-to-point ip ospf cost 400

SW7:

router ospf 1 router-id 10.3.0.3 passive-interface default no passive-interface FastEthernet1/1 no passive-interface Vlan901 network 10.3.0.3 0.0.0.0 area 0 network 10.3.1.4 0.0.0.3 area 0 network 10.3.1.12 0.0.0.3 area 0 network 10.67.1.0 0.0.0.255 area 0 network 10.131.1.0 0.0.0.255 area 0 int f1/1 ip ospf network point-to-point int vlan 901 ip ospf network point-to-point ip ospf cost 400

SW8:

router ospf 1 router-id 10.3.0.4 passive-interface default no passive-interface FastEthernet1/1 no passive-interface Vlan901 network 10.3.0.4 0.0.0.0 area 0 network 10.3.1.8 0.0.0.3 area 0 network 10.3.1.12 0.0.0.3 area 0 network 10.67.1.0 0.0.0.255 area 0 network 10.131.1.0 0.0.0.255 area 0 int f1/1

ip ospf network point-to-point

int vlan 901

ip ospf network point-to-point

ip ospf cost 400湖南省网调测： RT13: router ospf 1

router-id 10.4.0.1

redistribute connected metric 1000 metric-type 1 subnets

passive-interface FastEthernet2/0

network 10.4.0.1 0.0.0.0 area 0

network 10.4.1.0 0.0.0.3 area 0

network 10.4.1.4 0.0.0.3 area 0

default-information originate always metric 3000 metric-type 1

int f3/0

ip ospf network point-to-point

int f1/0

ip ospf network point-to-point

ip ospf cost 400

RT14:

router ospf 1

router-id 14.14.14.14

redistribute connected metric 1000 metric-type 1 subnets

passive-interface FastEthernet2/0

network 10.4.0.2 0.0.0.0 area 0

network 10.4.1.0 0.0.0.3 area 0

network 10.4.1.8 0.0.0.3 area 0

default-information originate always metric 3000 metric-type 1

int f3/0

ip ospf network point-to-point

int f1/0

ip ospf network point-to-point

ip ospf cost 400

SW11:

router ospf 1

router-id 10.4.0.3

passive-interface default

no passive-interface f1/1

no passive-interface vlan 901

network 10.4.0.3 0.0.0.0 area 0

network 10.4.1.4 0.0.0.3 area 0









neighbor as65000-rrc update-source Loopback0 neighbor as65000-rrc route-reflector-client neighbor as65000-rrc next-hop-self neighbor 10.0.0.3 peer-group as65000-rrc neighbor 10.0.0.4 peer-group as65000-rrc neighbor 10.0.0.5 peer-group as65000-rrc neighbor 10.0.0.6 peer-group as65000-rrc no auto-summary

ip route 10.0.0.0 255.255.0.0 Null0RT3： router bgp 65000

no synchronization neighbor 10.0.0.1 remote-as 65000 neighbor 10.0.0.1 update-source Loopback0 neighbor 10.0.0.1 next-hop-self neighbor 10.0.0.2 remote-as 65000 neighbor 10.0.0.2 update-source Loopback0 neighbor 10.0.0.2 next-hop-self neighbor 10.0.9.2 remote-as 65001 no auto-summary

RT4：

router bgp 65000 no synchronization neighbor 10.0.0.1 remote-as 65000 neighbor 10.0.0.1 update-source Loopback0 neighbor 10.0.0.1 next-hop-self neighbor 10.0.0.2 remote-as 65000 neighbor 10.0.0.2 update-source Loopback0 neighbor 10.0.0.2 next-hop-self neighbor 10.0.9.6 remote-as 65001 no auto-summary

RT5: router bgp 65000

no synchronization neighbor 10.0.0.1 remote-as 65000 neighbor 10.0.0.1 update-source Loopback0 neighbor 10.0.0.1 next-hop-self neighbor 10.0.0.2 remote-as 65000 neighbor 10.0.0.2 update-source Loopback0 neighbor 10.0.0.2 next-hop-self neighbor 10.0.9.10 remote-as 65002 no auto-summary

RT6:

router bgp 65000 no synchronization neighbor 10.0.0.1 remote-as 65000 neighbor 10.0.0.1 update-source Loopback0 neighbor 10.0.0.1 next-hop-self neighbor 10.0.0.2 remote-as 65000 neighbor 10.0.0.2 update-source Loopback0 neighbor 10.0.0.2 next-hop-self neighbor 10.0.9.14 remote-as 65002 no auto-summary

湖北省出口 BGP配置：

RT9:

router bgp 65001 no synchronization network 10.3.0.0 mask 255.255.0.0 network 10.67.0.0 mask 255.255.0.0 network 10.131.0.0 mask 255.255.0.0 neighbor 10.0.9.1 remote-as 65000 neighbor 10.3.0.2 remote-as 65001 neighbor 10.3.0.2 update-source Loopback0 neighbor 10.3.0.2 next-hop-self no auto-summary

ip route 10.3.0.0 255.255.0.0 Null0 ip route 10.67.0.0 255.255.0.0 Null0 ip route 10.131.0.0 255.255.0.0 Null0

RT10:

router bgp 65001 no synchronization network 10.3.0.0 mask 255.255.0.0 network 10.67.0.0 mask 255.255.0.0 network 10.131.0.0 mask 255.255.0.0 neighbor 10.0.9.5 remote-as 65000 neighbor 10.3.0.1 remote-as 65001 neighbor 10.3.0.1 update-source Loopback0 neighbor 10.3.0.2 next-hop-self no auto-summary

ip route 10.3.0.0 255.255.0.0 Null0 ip route 10.67.0.0 255.255.0.0 Null0 ip route 10.131.0.0 255.255.0.0 Null0

湖南省出口 BGP配置：

RT13：

router bgp 65002 no synchronization network 10.68.0.0 mask 255.255.0.0 network 10.132.0.0 mask 255.255.0.0 network 10.4.0.0 mask 255.255.0.0 neighbor 10.0.9.9 remote-as 65000 neighbor 10.4.0.2 remote-as 65002 neighbor 10.4.0.2 update-source Loopback0 no auto-summary

ip route 10.4.0.0 255.255.0.0 Null0 ip route 10.68.0.0 255.255.0.0 Null0 ip route 10.132.0.0 255.255.0.0 Null0RT14： router bgp 65002

no synchronization network 10.4.0.0 mask 255.255.0.0 network 10.68.0.0 mask 255.255.0.0 network 10.132.0.0 mask 255.255.0.0 neighbor 10.0.9.13 remote-as 65000 neighbor 10.4.0.1 remote-as 65002 neighbor 10.4.0.1 update-source Loopback0 no auto-summary

ip route 10.4.0.0 255.255.0.0 Null0 ip route 10.68.0.0 255.255.0.0 Null0 ip route 10.132.0.0 255.255.0.0 Null0

四、路由传播控制

省网只向全国骨干通告本 AS的路由

RT9： ip as-path access-list 10 permit ^$ router bgp 65001 neighbor 10.0.9.1 filter-list 10 out RT10: ip as-path access-list 10 permit ^$ router bgp 65001 neighbor 10.0.9.5 filter-list 10 out RT13:ip as-path access-list 10 permit ^$

router bgp 65002 neighbor 10.0.9.9 filter-list 10 out RT14: ip as-path access-list 10 permit ^$ router bgp 65002 neighbor 10.0.9.13 filter-list 10 out

全国骨干网只允许省网通告该省的路由

RT3： ip prefix-list hubei seq 5 permit 10.3.0.0/16 ip prefix-list hubei seq 10 permit 10.67.0.0/16 ip prefix-list hubei seq 15 permit 10.131.0.0/16 router bgp 65000 neighbor 10.0.9.2 prefix-list hubei in RT4: ip prefix-list hubei seq 5 permit 10.3.0.0/16 ip prefix-list hubei seq 10 permit 10.67.0.0/16 ip prefix-list hubei seq 15 permit 10.131.0.0/16 router bgp 65000 neighbor 10.0.9.6 prefix-list hubei in RT5: ip prefix-list hunan seq 5 permit 10.4.0.0/16 ip prefix-list hunan seq 10 permit 10.68.0.0/16 ip prefix-list hunan seq 15 permit 10.132.0.0/16 router bgp 65000 neighbor 10.0.9.10 prefix-list hunan in RT6: ip prefix-list hunan seq 5 permit 10.4.0.0/16 ip prefix-list hunan seq 10 permit 10.68.0.0/16 ip prefix-list hunan seq 15 permit 10.132.0.0/16 router bgp 65000 neighbor 10.0.9.14 prefix-list hunan in

五、BGP业务分流

RT9： ip prefix-list BG seq 5 permit 10.129.0.0/16 ip prefix-list BG seq 10 permit 10.132.0.0/16 ip prefix-list SC seq 5 permit 10.65.0.0/16 ip prefix-list SC seq 10 permit 10.68.0.0/16 route-map hubei permit 10

match ip address prefix-list SC set local-preference 500 route-map hubei permit 20

match ip address prefix-list BG

set metric 1000 route-map hubei permit 30 router bgp 65001 neighbor 10.0.9.1 route-map hubei inRT13： ip prefix-list BG seq 5 permit 10.129.0.0/16 ip prefix-list BG seq 10 permit 10.131.0.0/16 ip prefix-list SC seq 5 permit 10.65.0.0/16 ip prefix-list SC seq 10 permit 10.67.0.0/16 route-map hunan permit 10

match ip address prefix-list SC set local-preference 500

route-map hunan permit 20 match ip address prefix-list BG set metric 1000

route-map hunan permit 30 router bgp 65002

neighbor 10.0.9.9 route-map hunan in RT3: ip prefix-list BG seq 5 permit 10.131.0.0/16 ip prefix-list SC seq 5 permit 10.67.0.0/16 route-map hubei-in permit 10

match ip address prefix-list SC set local-preference 500

route-map hubei-in permit 20 match ip address prefix-list BG set metric 1000

route-map hubei-in permit 30 router bgp 65000

neighbor 10.0.9.2 route-map hubei-in in RT5: ip prefix-list BG seq 5 permit 10.132.0.0/16 ip prefix-list SC seq 5 permit 10.68.0.0/16 route-map hunan-in permit 10

match ip address prefix-list SC set local-preference 500

route-map hunan-in permit 20 match ip address prefix-list BG set metric 1000

route-map hunan-in permit 30 router bgp 65000 neighbor 10.0.9.2 route-map hunan-in in