NTP allows you to set the clocks on your systems very accurately, to within 100ms...

NTP allows you to set the clocks on your systems very accurately, to within 100ms and sometimes-even 10ms. Knowing the exact time is extremely important for enterprise security. Various security protocols depend on an accurate source of time information in order to prevent "playback" attacks. These protocols tag their communications with the current time, to prevent attackers from replaying the same communications, e.g., a login/password interaction or even an entire communication, at a later date. One can circumvent this tagging, if the clock can be set back to the time the communication was recorded. An attacker attempts to try corrupting the clocks on devices on your network. You run Wireshark to detect the NTP traffic to see if there are any irregularities on the network. What port number you should enable in Wireshark display filter to view NTP packets?