BGP federal experiment

  One ： Experimental topology and its requirements

  Two ; The topology diagram of subnet division

  3、 ... and ; experimental analysis （ Interface configuration has been omitted ）

        1,AS1 There are two loops , One address is 192.168.1.0/24 This address cannot be declared in any agreement ,AS3 There are two loops in , One address is 192.168.2.0/24 This address cannot be declared in any agreement , Finally, it is required that the two loops can communicate with each other .        AS1 The other loopback of is 10.0.0.0/24,AS3 The other loopback of is 11.0.0.0/24

These two network segments 192.168.1.0/24    192.168.2.0/24 Need to communicate , You need to establish a virtual link , Declare before passing 10.0.0.0 and 11.0.0.0 Virtual link construction between the two

        2, Whole AS2 Of IP The address is 172.16.0.0/16, Please divide reasonably
        3, AS Backbone link between IP The address can be customized at will

         See the topology diagram divided above
        4, Use BGP The protocol allows the loopback of all devices in the whole network to access each other

because AS There is a horizontal segmentation mechanism in the region , Routing information cannot be delivered , It can be solved by routing reflectors

        5, Reduce the number of routing entries , Avoid loop problems

Reduce routing entries in R2,R7 Route aggregation on , To avoid looping, you need to configure an empty interface

Four ： The configuration is as follows

R1;

 Build neighbors manually ;
[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)  

 The Internet 
[r1]bgp 1
[r1-bgp]net 10.0.0.0 24

 Set up a virtual link , Enable two undeclared networks to communicate 
[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;

 use OSPF build IGP Environmental Science （R2-R7 Are similar and will not be repeated one by one ）
[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 Build neighbors manually 
[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 


 Let the next hop of the sent routing information be modified to itself 
[r2]bgp 64512
[r2-bgp]peer 172.16.3.1 next-hop-local
[r2-bgp]peer 172.16.5.1 next-hop-local

 Empty interface configuration plus route aggregation （ hinder R7 The configuration is similar to , therefore R7 Configuration omitted ）
[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

 Configure the routing reflector （ break AS Horizontal segmentation within ）
[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 The configurations are consistent with those shown above , There is no display here

5、 ... and ; The results verify that

R1

 

 R2