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       walldns - a reverse DNS wall


       walldns  is  a  reverse DNS wall.  It accepts iterative DNS queries for domains from  hosts  around  the  Internet,  and  supplies
       generic responses that avoid revealing local host information.

       For  example,  walldns  provides  a PTR record for
       showing as the name of IP address,  and  a
       matching  A  record  showing  as the IP address of


       Normally walldns is set up by the walldns-conf(8) program.

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

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

Further details

       walldns  rejects inverse queries, non-Internet-class queries, truncated
       packets, packets that contain anything other than  a  single  question,
       queries  for domains outside, and request types other than
       A, PTR, and *.

       walldns does not include NS or SOA records with its responses.

       walldns uses TTLs slightly over one week.