Hi! I am looking for a way to permanently disable DNS Cache on macOS. This is well documented and easily done on Windows or Linux operating systems but somehow the internet is silent on how to get this implemented on Mac.
Any help is greatly appreciated! Thanks, Alik
Not sure if you can disable the DNS cache without disabling DNS completely.
To stop and continue queries try sudo killall -STOP mDNSResponder and sudo killall -CONT mDNSResponder. Also not sure what layers this affects and what they might cache.
You can still flush the DNS cache easily using sudo killall -HUP mDNSResponder so repeated calls might appear like a disabled cache. https://support.apple.com/en-us/HT202516
Use dns-sd -q apple.com to verify this:
dns-sd -Q apple.com
DATE: ---Tue 19 Jul 2022---
15:20:11.663 ...STARTING...
Timestamp A/R Flags if Name Type Class Rdata
15:20:11.664 Add 40000002 0 apple.com. Addr IN 17.253.144.10
15:20:14.156 Rmv 0 0 apple.com. Addr IN 17.253.144.10
15:20:14.166 Add 2 0 apple.com. Addr IN 17.253.144.10
Some historical commands are now deprecated with SIP and for security.
sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
/System/Library/LaunchDaemons/com.apple.mDNSResponder.plist: Operation not permitted while System Integrity Protection is engaged
man mDNSResponder
sudo killall -INFO mDNSResponder
Sending SIGINFO to mDNSResponder daemon is deprecated. To trigger state dump, please use 'dns-sd -O', enter 'dns-sd -h' for more information
sudo dns-sd -O
XPC service returns error, description: State dump is only enabled in internal builds
Thank you for your help! Is there a config file for mDNSResponder? I wonder if there could be a way to configure DNS Cache through that
What was the context / reason for disabling the DNS cache?
@mikeyh, at our enterprise we use and advanced DNS feature from Infoblox called Sort Lists. It assures multiple A records for a specific DNS name are return in a certain order, according to the subnet those records are associated with and the source network of the DNS client behind the query.
When those multiple A records end up in DNS Cache, local DNS resolver is not able to order them as expected, causing issues for our dev team. Therefore we need the Cache off.
