$ pydig -h
pydig (a DNS query tool written in Python), version 1.6.5

Usage: pydig [list of options] <qname> [<qtype>] [<qclass>]
       pydig @server +walk <zone>
Options:
        -h                        print program usage information
        @server                   server to query
        -pNN                      use port NN (default is port 53)
        -bIP                      use IP as source IP address
        +tcp                      send query via TCP
        +ignore                   ignore truncation (don't retry with TCP)
        +aaonly                   set authoritative answer bit
        +adflag                   set authenticated data bit
        +cdflag                   set checking disabled bit
        +norecurse                set rd bit to 0 (recursion not desired)
        +edns[=N]                 use EDNS with specified version (default 0)
        +ednsflags=N              set EDNS flags field to N
        +ednsopt=###[:value]      set generic EDNS option
        +bufsize=NN               use EDNS with specified UDP payload size
        +dnssec                   request DNSSEC RRs in response
        +hex                      print hexdump of rdata field
        +nsid                     send NSID (Name Server ID) option
        +expire                   send an EDNS Expire option
        +cookie[=xxx]             send EDNS cookie option
        +subnet=addr              send EDNS client subnet option
        +chainquery[=name]        send EDNS chain query option
        +padding[=N]              send EDNS padding option (defblocksize 128)
        +walk                     walk (enumerate) a DNSSEC secured zone
        +0x20                     randomize case of query name (bit 0x20 hack)
        +emptyquestion            send an empty question section
        +generic                  use RFC3597 generic type/class/rdata format
        -4                        perform queries using IPv4
        -6                        perform queries using IPv6
        -x                        reverse lookup of IPv4/v6 address in qname
        -d                        request additional debugging output
        -k/path/to/keyfile        use TSIG key in specified file
        -iNNN                     use specified message id
        -y<alg>:<name>:<key>      use specified TSIG alg, name, key
        +tls=auth|noauth          use TLS with|without authentication
        +tls_port=N               use N as the TLS port (default is 853)
        +tls_fallback             Fallback from TLS to TCP on TLS failure
        +tls_hostname=name        Check hostname in TLS server certificate
        +https[=url]              use HTTPS transport with optional URL
``

IXFR (Incremental Zone Transfer) queries are supported with the syntax
of "IXFR=NNNN" for the <qtype>, where NNNN is the zone serial number.

   pydig www.example.com
   pydig www.example.com A
   pydig www.example.com A IN
   pydig @10.0.1.2 example.com MX
   pydig @dns1.example.com _blah._tcp.foo.example.com SRV
   pydig @192.168.42.6 +dnssec +norecurse blah.example.com NAPTR
   pydig @dns2.example.com -6 +hex www.example.com
   pydig @192.168.72.3 +walk secure.example.com
   pydig @192.168.14.7 -yhmac-md5:my.secret.key.:YWxidXMgZHVtYmxlZG9yZSByaWNoYXJkIGRhd2tpbnM= example.com axfr
   pydig @192.168.14.7 -yhmac-sha256:my.secret.key.:NBGFWFr+rR/uu14B94Ab1+u81M2DTqB65gOv16nG8Xw= example.com axfr
   pydig @185.49.141.38 +tls=auth +tls_hostname=getdnsapi.net www.ietf.org AAAA
   pydig +padding=256 blah.example.com AAAA
   pydig +https www.ietf.org A

# Additional Notes

For TSIG (Transaction Signature) signed messages, the program supports
HMAC-MD5/SHA1/SHA256/SHA384/SHA256. It doesn't yet support GSS-TSIG.

It decodes but does not yet verify signatures in DNSSEC secured data.

It does not perform iterative resolution (eg. dig's +trace).

Specific features of TLS depend on the version of Python in use. TLS server
certificate verification and hostname verification require quite recent
versions of Python.

For +https, if no URL is specified, then by default Cloudflare's DNS over
HTTPS server is queried (https://cloudflare-dns.com/dns-query).


# Pre-requisites:

* Python 3
* "requests" module

# Installation:

1. pip3 install requests (if necessary)
2. python3 setup.py install

# License

Shumon Huque
E-mail: shuque -at- gmail.com
Web: https://www.huque.com/

Copyright (c) 2006 - 2017, Shumon Huque. 
All rights reserved. This program is free software; you can redistribute 
it and/or modify it under the same terms of the GNU General Public License.