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)