"Of course not," said the Mock Turtle. "Why, if a fish came to me, and told me he was going on a journey, I should say, `With what porpoise?'"
"Don't you mean `purpose'?" said Alice.
"I mean what I say," the Mock Turtle replied, in an offended tone. And the Gryphon added, "Come, let's hear some of your adventures."
In the last two chapters, we've demonstrated how to use nslookup and dig, and how to read the nameserver's debugging information. In this chapter, we'll show you how to use these tools—plus traditional Unix networking tools like trusty ol' ping—to troubleshoot real-life problems with DNS and BIND.
Troubleshooting, by its nature, is a tough subject to teach. You start with any of a world of symptoms and try to work your way back to the cause. We can't cover the whole gamut of problems you may encounter on the Internet, but we will certainly do our best to show how to diagnose the most common of them. And along the way, we hope to teach you troubleshooting techniques that will be valuable in tracking down more obscure problems that we don't document.
Before we launch into a discussion of how to troubleshoot a DNS or BIND problem, we should make sure you know how to tell whether a problem is caused by DNS as opposed to NIS. On hosts running NIS, figuring out whether the culprit is DNS or NIS can be difficult. The stock BSD nslookup, for example, doesn't pay any attention to NIS. You can run nslookup on a Sun ...