Bind 9 Administrator Reference Manual

Chapter 6. BIND 9 Conﬁguration Reference

stub A stub zone is similar to a slave zone, except that it replicates only the

NS records of a master zone instead of the entire zone. Stub zones are not a

standard part of the DNS; they are a feature speciﬁc to the BIND

implementation.

Stub zones can be used to eliminate the need for glue NS record in a

parent zone at the expense of maintaining a stub zone entry and a set of

name server addresses in named.conf. This usage is not

recommended for new configurations, and BIND 9

supports it only in a limited way. In BIND 4/8, zone

transfers of a parent zone included the NS records

from stub children of that zone. This meant that, in

some cases, users could get away with configuring

child stubs only in the master server for the parent

zone. BIND 9 never mixes together zone data from

different zones in this way. Therefore, if a BIND 9

master serving a parent zone has child stub zones

configured, all the slave servers for the parent zone

also need to have the same child stub zones

configured.

Stub zones can also be used as a way of forcing the

resolution of a given domain to use a particular set

of authoritative servers. For example, the caching

name servers on a private network using RFC2157

addressing may be configured with stub zones for

10.in-addr.arpa to use a set of internal name servers

as the authoritative servers for that domain.

forward A "forward zone" is a way to conﬁgure forwarding on a per-domain

basis. A zone statement of type forward can contain a forward and/or

forwarders statement, which will apply to queries within the domain

given by the zone name. If no forwarders statement is present or an

empty list for forwarders is given, then no forwarding will be done for

the domain, canceling the effects of any forwarders in the options

statement. Thus if you want to use this type of zone to change the

behavior of the global forward option (that is, "forward ﬁrst to", then

"forward only", or vice versa, but want to use the same servers as set

globally) you need to respecify the global forwarders.