Comprehensive experiment BGP

First divide the network segment and configure it, as shown below

Then establish neighbors on each router (Note: AR1, 2 and AR7,8 use the interface to directly connect to establish neighbors and the maximum number of hops needs to be changed. The reason why the interface is used to establish neighbors is because the question is only given on AR1, 8A loopback, if it is used to build neighbors, then the client is useless)

The AR8 is used here as an example

The command has only one line

AR1,2 same as above

Remember to write static when establishing neighbors in different areas, and declare the same with OSPF or RIP

Take AR6 as an example

The following is the neighbor building between different small ASs 64512 and 64513 between the same big AS2, let's look at 512 first

Take AR3 as an example

The same small ASs also establish neighbors directly according to the instructions. 512 and 513 are exactly the same. You can change the IP of the opposite end, mainly between AR2,5 and AR3,7, because they belong to different small ASs, so the maximum number of hopsAlso change it to 2, Then remember to write the big AS area they belong to as 2, and it must be written in front

As shown

Pay special attention to the red line. I failed to build a neighbor because I wrote the big AS to the back, and I have not found any errors after searching for a long time. Be sure to remember the order of writing

Then write the second loopback on AR2-7 as a terminal, just announce it with BGP after writing it

Simple command, just repeat the command on AR2-7, then ping to check if it works

Ping each other within the AS2 area

Then let the external AS area also ping, to improve the accuracy of the experiment

You can see that it is ok, then it proves that there is no problem in the front, and you can proceed to the last step

ip aggregation

The location of the aggregation is on AR2 and AR7, because they are two routers connecting AS1 and AS3, and they have to pass through them when passing the route out, so they are aggregated on them

What we want is not to specify, use the above

Take AR7 as an example

Then go to AR8 to view

Before Aggregation

After aggregation

This experiment is over