NAME

       rbldns - an IP-address-listing DNS server

DESCRIPTION

       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.

CONFIGURATION

       Normally rbldns is set up by the rbldns-conf program.

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

       rbldns listens for incoming UDP packets addressed to port 53 of $IP.
       It does not listen for TCP queries.  Specifying 0.0.0.0 or :: results
       in listing to all available IP addresses and interfaces (for IPv6)
       resectivey. In case $IP is specified as the pseudo IP address :0 rbldns
       is forced to bind to all available IPv4 and IPv6 addresses
       simultaneously.


       rbldns handles IPv4 domains of the form d.c.b.a.base where a.b.c.d is
       the IPv4 address in question and base is given by the $BASE environment
       variable.

       rbldns handles IPv6 domains of the form z.y.x...d.c.b.a.base where
       z.y.x...d.c.b.a.base is the IPv6 address in question and base is given
       by the $BASE environment variable.  While particular host addresses can
       be given, only the relevant 64 routing bits can be specified.

       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 $BASE.
       It looks up other queries inside data.cdb, a binary file created by
       rbldns-data.

SEE ALSO

       rbldns-conf(8), rbldns-data(8)

REFERENCE

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