DNS on Windows Server 2003, 3rd Edition

Planning for Disasters

It’s a fact of life on a network that things go wrong. Hardware fails, software has bugs, and people occasionally make mistakes. Sometimes this results in minor inconveniences, like having a few users lose connections. Sometimes the results are catastrophic and involve the loss of important data and valuable jobs.

Because the Domain Name System relies so heavily on the network, it is vulnerable to network outages. Thankfully, the design of DNS takes into account the imperfection of networks: it allows for multiple, redundant name servers, retransmission of queries, retrying zone transfers, and so on.

DNS doesn’t protect itself from every conceivable calamity, though. DNS doesn’t or can’t protect against certain types of network failures—some of them quite common. But with a small investment of time and money, you can minimize the threat of these problems.