Apr 04, 2020

sudo ufw allow 123/udp sudo ufw allow out 123/udp sudo ufw allow out 53 I've allowed UDP port 123 for both incoming and outgoing traffic to NTP work. Additionally I also needed to open TCP port 53 (DNS) for outgoing traffic since /etc/ntp.conf contains domain names of NTP servers. . Ubuntu - UDP Traffic on port 123 - Unix & Linux Stack Exchange UDP port 123 is the default NTP port. So check your NTP configuration. The most probably it's standard synchronization. You'd have to capture packets with tcpdump and inspect the content (wireshark). Solved: Different between port 123 (ntp) and 37 (timeserve Port 37 has been obsolete for a very long time and is one of the many archaic ports that should be disabled. NTP does not use 37 at all, only port 123. I would disable the following services in inetd.conf immediately, even if the security team has not reported them: daytime time echo discard chargen ntalk uucp help with connecting to NIST NTP server on port 123

Right-click your system clock located in the Windows task bar. Select "Adjust Date/Time" to open the …

22.14. Configure the Firewall to Allow Incoming NTP To enable NTP to pass through the firewall, using the graphical tool system-config-firewall, issue the following command as root: ~]# system-config-firewall The Firewall Configuration window opens. Select Other Ports from the list on the left. Click Add.The Port and Protocol window opens. Click on one of the port numbers and start typing 123.Select the “ port 123 ” entry with udp as the Setup local NTP servers - MikroTik Wiki

iptables - ubuntu: open udp port 123 - Server Fault

Still blocking ntp ports for outbound 123? | AT&T Jan 17, 2017 Opening UDP port 123 - Cisco Community