demand
1. First divide the AS internal address
2. Enable ospf protocol in AS
Because there is no special area and its summary, and only area0, the configuration process here is too simple, so I won’t go into details.
3. Start configuring the BGP protocol
R1 and R8 are establishing BGP neighbors (because there is only one route between AS and AS, the interface is used to establish neighbors)
R2 (neighboring with R1, R5R3)
The configuration of R3
R4
R5-R8 is similar to R1-R4, so I won't go into details.
R3 and R6 can be used as reflectors
peer 172.16.0.1 reflect-client
Then declare its own loopback, and announce all loopbacks of the federation on R2 and R4. (The same on R5 and R7).
But at this time, you will find that the 10.1.1.0 route is not optimal on R3, and there is no table added. (The reason is that the next hop is unknown network segment). At this time, you need to modify the next hop to be yourself on R2
peer 172.16.1.1 next-hop-local
The process will not be repeated. Did not hit the loop (maybe because of luck)
Add table to all routes learned by BGP
In the first requirement, the 192.168.1.0 and 192.168.2.0 network segments are no longer declared in any protocol to communicate with each other. (It turned out to use GRE)
Summarize, reduce routing entries
Because of the rubbish of the address division, it is difficult to summarize,
so one of the backbones in the federation is changed to
172.16.5.0 24
172.16.69.0 24
[r2-bgp]aggregate 172.16.0.0 22 detail-suppressed
[r4-bgp]aggregate 172.16.0.0 22 detail-suppressed
[r5-bgp]aggregate 172.16.64.0 22 detail-suppressed
[r7-bgp]aggregate 172.16.64.0 22 detail-suppressed
Route after summary
test:
to sum up:
In this experiment, one of my address masks was wrong, which caused BGP to fail to establish a neighbor (18 is matched to 28); and the address was mismatched; but the error is not panic, it is nothing more than checking the result analysis process; if it fails, use the packet capture tool to see See why this interface can't establish neighbors. It's all small details, fortunately. Address division is still a delicate task. Finally, the backbone routing network segment is modified to make the loopback address summary in AS2 more successful.