MacOS – Manually clear dns cache on mavericks

dnsmacos

My DNS cache is broken for a few websites (most notably codeship.com) so I need to clear it.

As instructed on numerous websites I've run

dscacheutil -flushcache; sudo killall -HUP mDNSResponder

in various permutations, including rebooting, but it has no effect.

When running dig I get no ANSWER SECTION, but I don't know how to interpret the rest of the info.

; <<>> DiG 9.8.3-P1 <<>> codeship.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 15470
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;codeship.com.          IN  A

;; Query time: 54 msec
;; SERVER: 192.168.1.1#53(192.168.1.1)
;; WHEN: Mon Dec  1 23:37:49 2014
;; MSG SIZE  rcvd: 30

Best Answer

Please check RFC1035, DNS protocol and Understanding the dig command. If the status is SERVFAIL (Server failure. The name server was unable to process this query due to a problem with the name server) you won't get an ANSWER section.

I don't think the problem is on your side.

In 7 attempts querying several name servers i only got one answer: 

dig @208.67.220.220 codeship.com
; <<>> DiG 9.8.5-P1 <<>> codeship.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36214
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;codeship.com.          IN  A

;; ANSWER SECTION:
codeship.com.       0   IN  A   54.243.124.75
codeship.com.       0   IN  A   54.225.96.71
codeship.com.       0   IN  A   54.221.223.218

;; Query time: 6126 msec
;; SERVER: 208.67.220.220#53(208.67.220.220)
;; WHEN: Tue Dec 02 02:03:36 CET 2014
;; MSG SIZE  rcvd: 78
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