# 0b10

Two-Bit History

Computing through
the ages

• If you fire up dig and run a DNS query for google.com, you will get a response somewhat like the following:

\$ dig google.com

; <<>> DiG 9.10.6 <<>> google.com
;; global options: +cmd
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27120
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:

The output contains both a section describing the “question” you asked (“What is the IP address of google.com?”) and a section describing the answer you received. In the answer section, we see that dig found a single record with what looks to be five fields. The record’s type is indicated by the A in the fourth field from the left—this is an “address” record. To the right of the A, in the fifth field, we can see that the IP address for google.com is 216.58.192.206. The 194 value in the second field specifies how long in seconds this particular record can be cached.