Virtual links: Yea or nay?

- [Instructor] I already mentioned this a couple of times…to you in this part of the course,…and probably several other parts of the course,…but one of the most important facets of troubleshooting…is knowing when to troubleshoot and when you don't have to.…Because in the real world of course you don't want to…waste time troubleshooting something that's working…just fine and secondly on the exam of course,…you know even in a multiple choice question you could get…something along the lines of, you know,…well is any troubleshooting needed here at all?…Or your answer would be well no.…Well in this particular case before we look at…the live equipment, is there a problem here?…Specifically with this particular topology,…is router one going to see router four's loopback,…and I haven't built in any surprises, anything like that,…I promise you, just going to have to take my word for it…because I've already done the config,…but we've got Area 0 over routers one, two and three,…that's our 172.12.123/24 network,…and we have three loopbacks all in Area 0.…