Check if DNS caching is enabled or disabled?

Ryan_G

Member
Nov 2, 2017
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Root Administrator
Is it possible to check if DNS caching is enabled with WHM? I have read this Stack Overflow Thread which states:

"On Linux (and probably most Unix), there is no OS-level DNS caching unless nscd is installed and running. Even then, the DNS caching feature of nscd is disabled by default"

I have checked in WHM service status on my VPS and I can see that nscd is installed an running but I can't work out how to check the settings to see if the DNS caching feature is enabled or disabled.

How can I check?
 

Ryan_G

Member
Nov 2, 2017
6
0
1
UK
cPanel Access Level
Root Administrator
Thanks for your help - I managed to get this (file contents below). Am I right in thinking that 'hosts' is the section that refers to DNS caching and that this shows that DNS caching is on?

#
# /etc/nscd.conf
#
# An example Name Service Cache config file. This file is needed by nscd.
#
# Legal entries are:
#
# logfile <file>
# debug-level <level>
# threads <initial #threads to use>
# max-threads <maximum #threads to use>
# server-user <user to run server as instead of root>
# server-user is ignored if nscd is started with -S parameters
# stat-user <user who is allowed to request statistics>
# reload-count unlimited|<number>
# paranoia <yes|no>
# restart-interval <time in seconds>
#
# enable-cache <service> <yes|no>
# positive-time-to-live <service> <time in seconds>
# negative-time-to-live <service> <time in seconds>
# suggested-size <service> <prime number>
# check-files <service> <yes|no>
# persistent <service> <yes|no>
# shared <service> <yes|no>
# max-db-size <service> <number bytes>
# auto-propagate <service> <yes|no>
#
# Currently supported cache names (services): passwd, group, hosts, services
#


# logfile /var/log/nscd.log
# threads 4
# max-threads 32
server-user nscd
# stat-user somebody
# reload-count 5
paranoia no
# restart-interval 3600

enable-cache passwd yes
positive-time-to-live passwd 600
negative-time-to-live passwd 20
suggested-size passwd 211
check-files passwd yes
persistent passwd yes
shared passwd yes
max-db-size passwd 33554432
auto-propagate passwd yes

enable-cache group yes
positive-time-to-live group 3600
negative-time-to-live group 60
suggested-size group 211
check-files group yes
persistent group yes
shared group yes
max-db-size group 33554432
auto-propagate group yes

enable-cache hosts yes
positive-time-to-live hosts 3600
negative-time-to-live hosts 20
suggested-size hosts 211
check-files hosts yes
persistent hosts yes
shared hosts yes
max-db-size hosts 33554432

enable-cache services yes
positive-time-to-live services 28800
negative-time-to-live services 20
suggested-size services 211
check-files services yes
persistent services yes
shared services yes
max-db-size services 33554432

enable-cache netgroup yes
positive-time-to-live netgroup 28800
negative-time-to-live netgroup 20
suggested-size netgroup 211
check-files netgroup yes
persistent netgroup yes
shared netgroup yes
max-db-size netgroup 33554432
 

cPanelLauren

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Nov 14, 2017
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