.TH rbldns 8

.SH NAME
rbldns \- an IP-address-listing DNS server

.SH DESCRIPTION
.B rbldns
is an IP-address-listing DNS server.
It accepts iterative DNS queries
from hosts around the Internet asking about various IP addresses.
It provides responses showing whether the addresses
are on a locally configured list,
such as RBL or DUL.

.SH Configuration
Normally 
.B rbldns
is set up by the
.BR rbldns-conf (8)
program.

.B rbldns
runs chrooted in the directory
specified by the 
.I $ROOT
environment variable,
under the uid and gid
specified by the 
.I $UID
and 
.I $GID
environment variables.

.B rbldns
listens for incoming UDP packets
addressed to port 53 of 
.IR $IP .
It does not listen for TCP queries.

.B rbldns
handles domains of the form
.IR d.c.b.a\fR.\fIbase
where 
.I a.b.c.d
is the IP address in question
and 
.I base
is given by the 
.I $BASE
environment variable.

.B rbldns
rejects
inverse queries, non-Internet-class queries, truncated packets,
packets that contain anything other than a single query,
query types other than A, TXT, or *,
and queries for domains outside 
.IR $BASE .
It looks up other queries inside 
.IR data.cdb ,
a binary file created by
.BR rbldns-data (8).

.SH SEE ALSO
rbldns-conf(8),
rbldns-data(8)

http://cr.yp.to/djbdns.html