What will happen if I close UDP_OUT port 123, the NTP port?

jols

Well-Known Member
Mar 13, 2004
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3
168
This may be a dumb question but - I may need to close this port for a while, i.e. UDP_OUT port 123, if I did, will whm/cpanel still be able to sync with an external time server?

As an adjunct, does anyone know how to update the NTP system on the server?
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,250
463
Hello :)

Closing port 123 would prevent time synchronization via the "ntpdate" command. However, you could use "rdate" to synchronize the server time instead. For example:

Code:
# rdate -s rdate.cpanel.net
"rdate" requires TCP outbound traffic over port 37.

Thank you.