How to view DNS cache in OSX?

dns osx-elcapitan oscache
Praseetha KR picture Praseetha KR · Aug 10, 2016 · Viewed 37.8k times · Source

To list the entries of DNS cache in OSX 10.11.6, I tried dscacheutil -statistics but that didn't work.

$ sudo dscacheutil -statistics
Unable to get details from the cache node

How can I just print what is there in the DNS cache without flushing it?

Answer

Praseetha KR picture Praseetha KR · Aug 10, 2016

mDNSResponder (multicast DNS daemon) SIGINFO signal can dump a snapshot summary of the internal state to /var/log/system.log, including the cache details. To do this:

Keep system log opened in one terminal:

tail -f /private/var/log/system.log

Send a SIGINFO signal to mDNSResponder from another terminal:

sudo killall -INFO mDNSResponder

Then check the logs in first terminal, you would be able to see cache dump:

mDNSResponder[98]: ------------ Cache -------------
mDNSResponder[98]: Slt Q     TTL if     U Type rdlen
mDNSResponder[98]:  52      1827 -U-      CNAME   17 www.sublimetext.com. CNAME sublimetext.com.
...
...
mDNSResponder[98]: Cache currently contains 154 entities; 3 referenced by active questions

(For more info: man mDNSResponder)

Related questions

How do I solve the "server DNS address could not be found" error on Windows 10?

After installing Windows 10, I am continuously getting the "server DNS address could not be found" error. I will be able to use the Internet for 4-5 minutes, and after that for 20-25 min I will get the above error. How …

Read More
ssh: Could not resolve hostname [hostname]: nodename nor servname provided, or not known

I am trying to set up a VPN with a Raspberry Pi, and the first step is gaining the ability to ssh into the device from outside my local network. For whatever reason, this is proving to be impossible and …

Read More
How do I get a list of all subdomains of a domain?

I want to find out all the subdomains of a given domain. I found a hint which tells me to dig the authoritative Nameserver with the following option: dig @ns1.foo.bar some_domain.com axfr But this never works. …

Read More