NAME

       axfr-get - a DNS zone-transfer client.

       It  sends  a  zone-transfer  request  in  DNS-over-TCP  format  to  descriptor  7, reads the results from
       descriptor 6, and saves the results in a file.

SYNOPSIS

       Normally axfr-get is run under tcpclient(1), which sets up descriptors 6 and 7 as a TCP connection  to  a
       remote host.

       axfr-get z fn fn.tmp

DESCRIPTION

       axfr-get  performs a zone transfer for domain z.  It writes the results to fn.tmp in a format that can be
       used as input to tinydns-data(8).  If the  zone  transfer  completes  successfully,  axfr-get  atomically
       renames fn.tmp as fn.

       fn.tmp and fn must be on the same filesystem.

       axfr-get  writes  the  zone serial number as a comment at the top of fn.tmp.  It skips the zone transfer,
       leaving fn alone, if fn already exists,

       fn has a serial number matching the zone serial number, and both serial numbers are nonzero.

       Zone transfers often include duplicate records.  You should feed the axfr-get results through sort -u.

       axfr-get discards all records outside the domain z.  It accepts records in child zones, but it marks  all
       child  zones  as  non-authoritative,  so tinydns(8) will not report those records except as glue.  If you
       plan to merge the axfr-get results for a domain  and  a  child  of  the  same  domain,  creating  a  file
       authoritative  for  both  zones,  make  sure to eliminate records in the first output that are within the
       child zone.

       axfr-get will accept arbitrarily large zone transfers.  To limit the maximum file size to 1 megabyte, run
       axfr-get under softlimit -f 1048576.

Compatibility notes

       axfr-get handles BIND's RFC-1034-violating multiple-answers zone-transfer format.

       axfr-get  does  not  precisely  simulate  BIND's handling of *.dom.  Under BIND, records for *.dom do not
       apply to y.dom or anything.y.dom if there is a normal record for x.y.dom.  With axfr-get and  tinydns(8),
       the records apply to y.dom and anything.y.dom except x.y.dom.

       axfr-get  does  not  precisely simulate BIND's handling of multiple IP addresses for a single name.  When
       there are more than 8 addresses, tinydns(8) selects a random set of 8 for each query.

SEE ALSO

       axfrdns(8), tinydns(8), tinydns-data(8), tcpclient(1), softlimit(8) http://cr.yp.to/djbdns.html

                                                                                                     axfr-get(8)