DNS on Windows Server 2003, 3rd Edition

Really Long Outages (Weeks)

If an extended outage cuts you off from the Internet—say for a week or more—you may need to restore connectivity to root name servers artificially to get things working again. Every name server needs to talk to a root name server occasionally. It’s a bit like therapy: the name server needs to contact the root to regain its perspective on the world.

To provide root name service during a long outage, you can set up your own root name servers, but only temporarily. Once you’re reconnected to the Internet, you must shut off your temporary root servers. The most obnoxious vermin on the Internet are name servers that believe they’re root name servers but don’t know anything about most top-level domains. A close second is the Internet name server configured to query—and report—a false set of root name servers.

That said, and our alibis in place, here’s what you have to do to configure your own root name server. First, you need to create the root zone. The root zone will delegate to the highest level zones in your isolated network. For example, if movie.edu were to be isolated from the Internet, we might create a root zone datafile, root.dns, for terminator:

. IN SOA terminator.movie.edu. al.robocop.movie.edu. ( 1 ; Serial 10800 ; Refresh after 3 hours 3600 ; Retry after 1 hour 604800 ; Expire after 1 week 86400 ) ; Minimum TTL of 1 day ; Refresh, retry, and expire really don't matter since all ; roots are primaries. Minimum TTL could be longer, since ; the data ...