Ensp's ospf small experiment

Claim:

Ideas:

1. First configure the IP address and then write the default to the ISP

2. Make the external network connectable (R1-R3 are similar)

3. Use MGRE (R1 as the central site, R2 and R3 as branch sites)

4. Enable ospf in the private network (R2 and R3 perform similar operations to announce the private network)

At this time, you will find that R1 only establishes an adjacency with one, while it is stuck in the init state with the other. Because MGRE is a point-to-multipoint network,
the ospf network type of the interface is changed to the broadcast type.
At this time, there will be DR and BDR elections. We hope that R1 will become DR so we modify the DR priority values ​​of R2 and R3.
[r3-Tunnel0/0/0]ospf dr-priority 1

Then restart the Tunnel port, then

5. View the routes learned by ospf

6. Test:

The experiment is complete.