bgp经典实验

bgp经典实验

dis bgp routing-table

邻居发现下一跳不可达的时候用peer 4.4.4.4 next-hop-local
next-hop-local给邻居用，发路由的时候改下一跳

默认情况下：
路由转发给ibgp邻居时，不会修改下一跳
路由转发给ebgp邻居时，自动修改下一跳
路由引入：在asbr上将bgp引入到igp中

bgp路由器收到一条来自于ibgp的路由，不会再发给其他ibgp邻居—–水平分割原则：防环
asbr收到来自ebgp邻居的路由之后，直接发给所有ibgp邻居，而在ibgp邻居之间，就不再互相转发该路由了

bgp 200
router-id 2.2.2.2 \\起名字
peer 4.4.4.4 as-number 200 \\建立邻居指明邻居as号
peer 4.4.4.4 connect-interface LoopBack0 \\设置与邻居通信的原接口，igbp建议使用环回口
peer 12.1.1.1 as-number 100 \\配置ebgp邻居关系
#
ipv4-family unicast \\IPV4地址族
undo synchronization
peer 3.3.3.3 enable \\自动启动邻居关系
peer 3.3.3.3 next-hop-local
peer 4.4.4.4 enable
peer 4.4.4.4 next-hop-local \\发路由给4.4.4.4时，修改下一跳为本地
peer 12.1.1.1 enable
bgp 100
network 1.1.1.1 255.255.255.255 \\宣告路由
bgp 300
router-id 5.5.5.5
peer 10.4.4.4 as-number 200
peer 10.4.4.4 ebgp-max-hop 2 \\EBGP邻居默认只能有一跳，修改为2跳
peer 10.4.4.4 connect-interface LoopBack10 \\使用环回口建立ebgp邻居
解法：全互联
ibgp全互联
R3也运行bgp,和R2,R4同时建立邻居关系，
ibgp内部放环规则
从ibgp邻居收到的路由不会再发给其他ibgp邻居，因此必须让R2/R3/R4全互联

AR1配置如下：

<AR1>dis cu
#
sysname AR1
#
interface GigabitEthernet0/0/0
ip address 12.1.1.1 255.255.255.0
#
interface LoopBack0
ip address 1.1.1.1 255.255.255.255
#
bgp 100
router-id 1.1.1.1
peer 12.1.1.2 as-number 200
#
ipv4-family unicast
undo synchronization
network 1.1.1.1 255.255.255.255
peer 12.1.1.2 enable

AR2配置如下：

<AR2>dis cu
#
sysname AR2
#
interface GigabitEthernet0/0/0
ip address 12.1.1.2 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 23.1.1.2 255.255.255.0
#
interface LoopBack0
ip address 2.2.2.2 255.255.255.255
#
bgp 200
router-id 2.2.2.2
peer 3.3.3.3 as-number 200
peer 3.3.3.3 connect-interface LoopBack0
peer 4.4.4.4 as-number 200
peer 4.4.4.4 connect-interface LoopBack0
peer 12.1.1.1 as-number 100
#
ipv4-family unicast
undo synchronization
peer 3.3.3.3 enable
peer 3.3.3.3 next-hop-local
peer 4.4.4.4 enable
peer 4.4.4.4 next-hop-local
peer 12.1.1.1 enable
#
ospf 1 router-id 2.2.2.2
import-route bgp
area 0.0.0.0
network 2.2.2.2 0.0.0.0
network 23.1.1.2 0.0.0.0

AR3配置如下：

<AR3>dis cu
#
sysname AR3
#
interface GigabitEthernet0/0/0
ip address 23.1.1.3 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 34.1.1.3 255.255.255.0
#
interface LoopBack0
ip address 3.3.3.3 255.255.255.255
#
bgp 200
router-id 3.3.3.3
peer 2.2.2.2 as-number 200
peer 2.2.2.2 connect-interface LoopBack0
peer 4.4.4.4 as-number 200
peer 4.4.4.4 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
peer 2.2.2.2 enable
peer 4.4.4.4 enable
#
ospf 1 router-id 3.3.3.3
area 0.0.0.0
network 3.3.3.3 0.0.0.0
network 23.1.1.3 0.0.0.0
network 34.1.1.3 0.0.0.0

AR4配置如下：

<AR4>dis cu
#
sysname AR4
#
interface GigabitEthernet0/0/0
ip address 34.1.1.4 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 45.1.1.4 255.255.255.0
#
interface LoopBack0
ip address 4.4.4.4 255.255.255.255
#
interface LoopBack10
ip address 10.4.4.4 255.255.255.255
#
bgp 200
router-id 4.4.4.4
peer 2.2.2.2 as-number 200
peer 2.2.2.2 connect-interface LoopBack0
peer 3.3.3.3 as-number 200
peer 3.3.3.3 connect-interface LoopBack0
peer 10.5.5.5 as-number 300
peer 10.5.5.5 ebgp-max-hop 2
peer 10.5.5.5 connect-interface LoopBack10
#
ipv4-family unicast
undo synchronization
peer 2.2.2.2 enable
peer 2.2.2.2 next-hop-local
peer 3.3.3.3 enable
peer 3.3.3.3 next-hop-local
peer 10.5.5.5 enable
#
ospf 1 router-id 4.4.4.4
import-route bgp
area 0.0.0.0
network 4.4.4.4 0.0.0.0
network 34.1.1.4 0.0.0.0
#
ip route-static 10.5.5.5 255.255.255.255 45.1.1.5

AR5配置如下：

<AR5>dis cu
#
sysname AR5
#
interface GigabitEthernet0/0/0
ip address 45.1.1.5 255.255.255.0
#
interface LoopBack0
ip address 5.5.5.5 255.255.255.255
#
interface LoopBack10
ip address 10.5.5.5 255.255.255.255
#
bgp 300
router-id 5.5.5.5
peer 10.4.4.4 as-number 200
peer 10.4.4.4 ebgp-max-hop 2
peer 10.4.4.4 connect-interface LoopBack10
#
ipv4-family unicast
undo synchronization
network 5.5.5.5 255.255.255.255
peer 10.4.4.4 enable
#
ip route-static 10.4.4.4 255.255.255.255 45.1.1.4