Thanks to everyone that participated in Contest #3. Here are the solutions to both questions:
Question 1: eBGP peering with Loopback interfaces
There are actually three possible solutions to this:
- Use the neighbor x.x.x.x ebgp-multihop 2 command
- Use the neighbor x.x.x.x disable-connected-check command
- Use the neighbor x.x.x.x ttl-security hops 2 command
Many people think that it takes two hops to get from the loopback interface of one router to the loopback interface of a directly connected router but this is not true: it actually takes just one hop. You can refer to this article that attempts to clear up this misunderstanding.