BGP联邦实验

 一：实验拓扑图及其要求

 二；子网划分好的拓扑图

 三；实验分析（接口配置已省略）

        1,AS1存在两个环回，一个地址为192.168.1.0/24该地址不能在任何协议中宣告，AS3中存在两个环回，一个地址为192.168.2.0/24该地址不能在任何协议中宣告，最终要求这两个环回可以互相通讯。        AS1的另一个环回为10.0.0.0/24，AS3的另一个环回为11.0.0.0/24

这俩个网段192.168.1.0/24    192.168.2.0/24需要通信，则需建立虚链路，通过之前宣告10.0.0.0和11.0.0.0俩进行虚链路搭建

        2，整个AS2的 IP地址为172.16.0.0/16，请合理划分
        3, AS 间的骨干链路 IP 地址随意定制

        见上划分好的拓扑图
        4，使用 BGP 协议让整个网络所有设备的环回可以互相访问

因为AS区域内存在水平分割机制，路由信息无法传递，可以通过路由反射器解决

        5，减少路由条目数量，避免环路出现

减少路由条目要在R2,R7上进行路由聚合，环路地避免则需要配置空接口

四：配置如下

R1;

手工建邻；
[r1]bgp 1
[r1-bgp]router-id 1.1.1.1 
[r1-bgp]peer 12.0.0.2 as-number 2
[r1-bgp]
Jul 24 2022 16:37:06-08:00 r1 %%01BGP/3/STATE_CHG_UPDOWN(l)[0]:The status of the
 peer 12.0.0.2 changed from OPENCONFIRM to ESTABLISHED. (InstanceName=Public, St
ateChangeReason=Up)  

宣告网络
[r1]bgp 1
[r1-bgp]net 10.0.0.0 24

建立虚链路，使俩个未宣告的网络可以通信
[r1]int t 0/0/0
[r1-Tunnel0/0/0]ip ad 90.0.0.1 24
[r1-Tunnel0/0/0]tunnel-protocol gre
[r1-Tunnel0/0/0]source 10.0.0.1
[r1-Tunnel0/0/0]destination 11.0.0.1
Jul 24 2022 17:24:39-08:00 r1 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP 
on the interface Tunnel0/0/0 has entered the UP state. 
[r1-Tunnel0/0/0]
[r1-Tunnel0/0/0]q
[r1]ip route-static 192.168.2.0 24 90.0.0.2

R2;

用OSPF搭建IGP环境（R2-R7均相似不再一一赘述）
[r2]ospf 1 router-id 2.2.2.2
[r2-ospf-1]a 0
[r2-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255

bgp手工建邻
[r2]bgp 64512
[r2-bgp]router-id 2.2.2.2
[r2-bgp]confederation id 2	
[r2-bgp]confederation peer-as 64513
[r2-bgp]peer 12.0.0.1 as-number 1
Jul 24 2022 16:37:06-08:00 r2 %%01BGP/3/STATE_CHG_UPDOWN(l)[10]:The status of th
e peer 12.0.0.1 changed from OPENCONFIRM to ESTABLISHED. (InstanceName=Public, S
tateChangeReason=Up)  
[r2-bgp]peer 172.16.3.1 as	
[r2-bgp]peer 172.16.3.1 as-path-filter
[r2-bgp]peer 172.16.3.1 as-number 64512
[r2-bgp]peer 172.16.3.1 connect-interface LoopBack 0
[r2-bgp]peer 172.16.5.1 as-number 64513
[r2-bgp]peer 172.16.5.1 connect-interface LoopBack 0	
[r2-bgp]peer 172.16.5.1 ebgp-max-hop 


让发出的路由信息下一跳修改为本身
[r2]bgp 64512
[r2-bgp]peer 172.16.3.1 next-hop-local
[r2-bgp]peer 172.16.5.1 next-hop-local

空接口配置加路由聚合（后面的R7配置相似，所以R7配置略）
[r2]ip route-static 172.16.0.0 21 NULL 0
[r2]bgp 64512
[r2-bgp]net 172.16.0.0 21

R3；

[r3]ospf 1 router-id 3.3.3.3
[r3-ospf-1]a 0
[r3-ospf-1-area-0.0.0.0]net 172.16.0.0 0.0.255.255


[r3]bgp 64512
[r3-bgp]router-id 3.3.3.3
[r3-bgp]confederation id 2
[r3-bgp]peer 172.16.2.1 as-number 64512
[r3-bgp]peer 172.16.2.1 connect-interface l 0
[r3-bgp]peer 172.16.4.1 as-number 64512
Jul 24 2022 16:43:40-08:00 r3 %%01BGP/3/STATE_CHG_UPDOWN(l)[0]:The status of the
 peer 172.16.2.1 changed from OPENCONFIRM to ESTABLISHED. (InstanceName=Public, 
StateChangeReason=Up)  
[r3-bgp]peer 172.16.4.1 connect-interface l 0

进行路由反射器配置（打破AS内的水平分割）
[r3]bgp 64512
[r3-bgp]peer 172.16.2.1 reflect-client 

R4;

[r4]ospf 1 router-id 4.4.4.4
[r4-ospf-1]a 0
[r4-ospf-1-area-0.0.0.0]net 172.16.0.0 0.0.255.255

[r4]bgp 64512
[r4-bgp]router-id 4.4.4.4	
[r4-bgp]confederation id 2
[r4-bgp]confederation peer-as 64513
[r4-bgp]peer 172.16.3.1 as 64512	
[r4-bgp]peer 172.16.3.1 connect-interface l 0
[r4-bgp]peer 172.16.7.1 as 64513 
Jul 24 2022 16:45:59-08:00 r4 %%01BGP/3/STATE_CHG_UPDOWN(l)[0]:The status of the
 peer 172.16.3.1 changed from OPENCONFIRM to ESTABLISHED. (InstanceName=Public, 
StateChangeReason=Up)  
[r4-bgp]peer 172.16.7.1 connect-interface  l 0
[r4-bgp]peer 172.16.7.1 ebgp-max-hop 

R5;

[r5]ospf 1 router-id 5.5.5.5
[r5-ospf-1]a 0
[r5-ospf-1-area-0.0.0.0]net 172.16.0.0 0.0.255.255

[r5]bgp 64513
[r5-bgp]router-id 5.5.5.5
[r5-bgp]confederation id 2	
[r5-bgp]confederation peer-as 64512
[r5-bgp]peer 172.16.2.1 as 64512
[r5-bgp]peer 172.16.2.1 connect-interface l 0
[r5-bgp]peer 172.16.6.1 as 64513
[r5-bgp]peer 172.16.6.1 connect-interface l 0	
[r5-bgp]peer 172.16.2.1 ebgp-max-hop 

R6-R7的配置均上文展示一致，这里便不在展示

五；结果验证

R1

 

 R2