实例最后保证两个在bgp里network发布的网段:ping -a 192.168.1.1 192.168.2.1 能通
配置思路:
1、首先配置基础的端口IP地址、回环接口地址、router-id
2、IBGP内部各相连接的物理接口先ospf打通。
3、EBGP间用直连接物理接口peer连接建立。
4、IBGP间用回环接口建立peer邻居,所有的回环地址必须在ospf里宣告,但不要宣告到bgp里去。
注意 :在IBGP建立邻居时peer ip地址 as 200 和peer ip地址 con loop 0 中的两个ip地址必须全为回环接口相同的地址,这个点容易错。
5、R2为边界路由要做:peer R3回环地址 next-hop-local ,不然R3收到的外部路由下一跳会指向R1的接口地址,造成R3不可达。
6、R3指定R4为RR-C
7、R4再指定R5为RR-C(如果不做这个R5的BGP宣告网段出不去)
8、R1的BGP里netwrol 宣告192.168.1.1,R5的BGP里network宣告192.168.2.1
R1:
interface GigabitEthernet0/0/0
ip address 12.1.1.1 255.255.255.0
#
interface LoopBack0
ip address 192.168.1.1 255.255.255.0
#
bgp 100
router-id 1.1.1.1
peer 12.1.1.2 as-number 200
network 192.168.1.0 24
R2
interface GigabitEthernet0/0/0
ip address 12.1.1.2 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 23.1.1.1 255.255.255.0
ospf enable 1 area 0.0.0.0
interface LoopBack0
ip address 2.1.1.1 255.255.255.0
ospf enable 1 area 0.0.0.0
#
bgp 200
router-id 2.2.2.2
peer 3.1.1.1 as-number 200
peer 3.1.1.1 connect-interface LoopBack0
peer 12.1.1.1 as-number 100
peer 3.1.1.1 next-hop-local
ospf 1
area 0.0.0.0
R3
interface GigabitEthernet0/0/1
ip address 23.1.1.2 255.255.255.0
ospf enable 1 area 0.0.0.0
#
interface GigabitEthernet0/0/2
ip address 34.1.1.1 255.255.255.0
ospf enable 1 area 0.0.0.0
#
interface LoopBack0
ip address 3.1.1.1 255.255.255.0
ospf enable 1 area 0.0.0.0
#
bgp 200
router-id 3.3.3.3
peer 2.1.1.1 as-number 200
peer 2.1.1.1 connect-interface LoopBack0
peer 4.1.1.1 as-number 200
peer 4.1.1.1 connect-interface LoopBack0
#
peer 4.1.1.1 reflect-client
#
ospf 1
area 0.0.0.0
R4
interface GigabitEthernet0/0/0
ip address 45.1.1.1 255.255.255.0
ospf enable 1 area 0.0.0.0
#
interface GigabitEthernet0/0/2
ip address 34.1.1.2 255.255.255.0
ospf enable 1 area 0.0.0.0
#
interface LoopBack0
ip address 4.1.1.1 255.255.255.0
ospf enable 1 area 0.0.0.0
#
bgp 200
router-id 4.4.4.4
peer 3.1.1.1 as-number 200
peer 3.1.1.1 connect-interface LoopBack0
peer 5.1.1.1 as-number 200
peer 5.1.1.1 connect-interface LoopBack0
peer 5.1.1.1 reflect-client
#
ospf 1
area 0.0.0.0
R5
interface GigabitEthernet0/0/0
ip address 45.1.1.2 255.255.255.0
ospf enable 1 area 0.0.0.0
#
interface LoopBack0
ip address 5.1.1.1 255.255.255.0
ospf enable 1 area 0.0.0.0
#
interface LoopBack1
ip address 192.168.2.1 255.255.255.0
#
bgp 200
router-id 5.5.5.5
peer 4.1.1.1 as-number 200
peer 4.1.1.1 connect-interface LoopBack0
network 192.168.2.0 24
#
ospf 1
area 0.0.0.0