- 名词解释
- BGP Speakers：运行BGP的路由器
- BGP peer=BGP Neighbors=BGP对等体/邻居
instance：display BGP peer//查看邻居
- 邻居关系建立在TCP连接基础上，因此邻居不一定需要直连，可以通过IGP或静态路由提供TCP连接的可达性
- 邻居必须手动指定，而非自动建立
- 一台BGP路由器只能运行在一个AS内
- BGP都是单播传递
- BGP邻居类型
- IBGP：内部BGP邻居，位于相同AS
- RBGP：外部BGP邻居，位于不同AS
- BGP邻居配置命令
- BGP 123:声明所在AS号（创建进程）
- router-id 1.1.1.1 ：配置rid，必须唯一
- peer 12.0.0.2 as-number 123：配置邻居IP地址和所在的AS号
- display bgp peer：显示BGP邻居状态
- 简单实例
1、基础配置
R1:
interface GigabitEthernet0/0/0
ip address 192.168.1.1 255.255.255.0
interface GigabitEthernet0/0/1
ip address 192.168.2.1 255.255.255.0
interface LoopBack0
ip address 1.1.1.1 255.255.255.255
R2:
interface GigabitEthernet0/0/0
ip address 192.168.1.2 255.255.255.0
interface GigabitEthernet0/0/1
ip address 10.1.1.1 255.255.255.252
interface LoopBack0
ip address 2.2.2.2 255.255.255.255
R3:
interface GigabitEthernet0/0/0
ip address 192.168.2.2 255.255.255.0
interface GigabitEthernet0/0/1
ip address 10.1.1.5 255.255.255.252
interface LoopBack0
ip address 3.3.3.3 255.255.255.255
R4:
interface GigabitEthernet0/0/0
ip address 10.1.1.2 255.255.255.252
interface LoopBack0
ip address 4.4.4.4 255.255.255.255
R5:
interface GigabitEthernet0/0/0
ip address 10.1.1.6 255.255.255.252
interface LoopBack0
ip address 5.5.5.5 255.255.255.255
2、配置区域内IGP
R1:
ospf 1 router-id 1.1.1.1
area 0.0.0.0
network 1.1.1.1 0.0.0.0
network 192.168.1.0 0.0.0.255
network 192.168.2.0 0.0.0.255
R2:
ospf 1 router-id 2.2.2.2
area 0.0.0.0
network 2.2.2.2 0.0.0.0
network 192.168.1.0 0.0.0.255
R3:
ospf 1 router-id 3.3.3.3
area 0.0.0.0
network 3.3.3.3 0.0.0.0
network 192.168.2.0 0.0.0.255
3、建立IBGP对等体
R1:
bgp 300
peer 2.2.2.2 as-number 300
peer 2.2.2.2 connect-interface LoopBack0
peer 3.3.3.3 as-number 300
peer 3.3.3.3 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
peer 2.2.2.2 enable
peer 3.3.3.3 enable
R2:
bgp 300
peer 1.1.1.1 as-number 300
peer 1.1.1.1 connect-interface LoopBack0
peer 3.3.3.3 as-number 300
peer 3.3.3.3 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
peer 1.1.1.1 enable
peer 3.3.3.3 enable
R3:
bgp 300
peer 1.1.1.1 as-number 300
peer 1.1.1.1 connect-interface LoopBack0
peer 2.2.2.2 as-number 300
peer 2.2.2.2 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
peer 1.1.1.1 enable
peer 2.2.2.2 enable
4、配置EBGP对等体
R2:
#
ip route-static 4.4.4.4 255.255.255.255 10.1.1.2
#
#
bgp 300
peer 1.1.1.1 as-number 300
peer 1.1.1.1 connect-interface LoopBack0
peer 3.3.3.3 as-number 300
peer 3.3.3.3 connect-interface LoopBack0
peer 4.4.4.4 as-number 100
peer 4.4.4.4 ebgp-max-hop 5
peer 4.4.4.4 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
peer 1.1.1.1 enable
peer 3.3.3.3 enable
peer 4.4.4.4 enable
#
R4：
#
bgp 100
peer 2.2.2.2 as-number 300
peer 2.2.2.2 ebgp-max-hop 5
peer 2.2.2.2 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
peer 2.2.2.2 enable
#
ip route-static 2.2.2.2 255.255.255.255 10.1.1.1
#
R3:
#
bgp 300
peer 1.1.1.1 as-number 300
peer 1.1.1.1 connect-interface LoopBack0
peer 2.2.2.2 as-number 300
peer 2.2.2.2 connect-interface LoopBack0
peer 5.5.5.5 as-number 200
peer 5.5.5.5 ebgp-max-hop 5
peer 5.5.5.5 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
peer 1.1.1.1 enable
peer 2.2.2.2 enable
peer 5.5.5.5 enable
#
ospf 1 router-id 3.3.3.3
area 0.0.0.0
network 3.3.3.3 0.0.0.0
network 192.168.2.0 0.0.0.255
#
ip route-static 5.5.5.5 255.255.255.255 10.1.1.6
#
R5：
#
bgp 200
peer 3.3.3.3 as-number 300
peer 3.3.3.3 ebgp-max-hop 5
peer 3.3.3.3 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
peer 3.3.3.3 enable
#
ip route-static 3.3.3.3 255.255.255.255 10.1.1.5
#
