How many addresses do you like on point-to-point circuits?
That will become one of those great interview questions, because anyone who says something like "a /127" or "a /64" will be someone that you probably don't want to hire. The right answer is to explain that there are some issues surrounding the choice of addressing on point-to-point circuits and there has even been an RFC published discussing these issues, RFC 3627 <http://www.ietf.org/rfc/rfc3627.txt> The right decision for one network, or for one point in the topology, might not be the right decision for some other place. Some people may learn this by rote as a rule to always use a /126 or a /112 for point-to-point links, but even then it is best to understand why. --Michael Dillon