Книга: Fedora™ Unleashed, 2008 edition

Delegation Problems

Delegation Problems

Your zone must be delegated to the nameservers authoritative for them, either by the root nameservers or the parents of the zone in question. Improper delegation can cause the name service for your domain to become dysfunctional, prevent some networks from using the name service, and numerous other problems. These problems typically occur only in the initial stages of setting up a domain when the delegations have not propagated widely yet.

If you experience such problems, you can use dig to follow delegation chains and find the point at which problems occur. A tool such as dnswalk might also be useful (see "Tools for Troubleshooting" later in this chapter).

Lame delegation is another common DNS delegation problem. Lame delegation occurs when a nameserver is listed as being authoritative for a zone, but in fact is not authoritative (it has not been configured to be a master for the zone); the nameserver in a lame delegation is called a lame server. Unfortunately, lame delegations are very common on the Internet. They can be the temporary result of domains being moved or (especially in the case of reverse zones) more permanent configuration errors that are never detected because of a lack of attention to detail.

If your registrar's bills for your domain are not promptly paid, the registrar might discontinue the delegation of authority for your zone. If this happens (and the whois record for your domain usually mentions this), the best thing to do is quickly pay the registrar and ask for a renewal of the delegation. It is better not to let it happen, however, because such changes can take a relatively long time to make and propagate.

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