dig md - Feature? Bug? What's going on?

[Matthew Horsfall (alh)]

Attempting to 'dig' for 'md' does something really weird. What am I missing?

mhorsfall at dumai:~$ dig m

  ; <<>> DiG 9.9.5-4.3ubuntu0.2-Ubuntu <<>> m
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 44519
  ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

  ;; QUESTION SECTION:
  ;m.                IN    A

  ;; Query time: 2 msec
  ;; SERVER: 127.0.1.1#53(127.0.1.1)
  ;; WHEN: Mon Jul 27 12:17:38 EDT 2015
  ;; MSG SIZE  rcvd: 19

mhorsfall at dumai:~$ dig d

  ; <<>> DiG 9.9.5-4.3ubuntu0.2-Ubuntu <<>> d
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 22301
  ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

  ;; QUESTION SECTION:
  ;d.                IN    A

  ;; Query time: 3 msec
  ;; SERVER: 127.0.1.1#53(127.0.1.1)
  ;; WHEN: Mon Jul 27 12:17:39 EDT 2015
  ;; MSG SIZE  rcvd: 19

mhorsfall at dumai:~$ dig md

  ; <<>> DiG 9.9.5-4.3ubuntu0.2-Ubuntu <<>> md
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14960
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 1

  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 1280
  ;; QUESTION SECTION:
  ;.                IN    NS

  ;; ANSWER SECTION:
  .            392353    IN    NS    l.root-servers.net.
  .            392353    IN    NS    b.root-servers.net.
  .            392353    IN    NS    g.root-servers.net.
  .            392353    IN    NS    k.root-servers.net.
  .            392353    IN    NS    i.root-servers.net.
  .            392353    IN    NS    c.root-servers.net.
  .            392353    IN    NS    h.root-servers.net.
  .            392353    IN    NS    m.root-servers.net.
  .            392353    IN    NS    a.root-servers.net.
  .            392353    IN    NS    d.root-servers.net.
  .            392353    IN    NS    j.root-servers.net.
  .            392353    IN    NS    f.root-servers.net.
  .            392353    IN    NS    e.root-servers.net.

  ;; Query time: 29 msec
  ;; SERVER: 127.0.1.1#53(127.0.1.1)
  ;; WHEN: Mon Jul 27 12:17:40 EDT 2015
  ;; MSG SIZE  rcvd: 239

-- Matthew Horsfall (alh)