What is the recommended way for handling NTP?

1. What protocol is used for NTP?
2. What is the recommended NTP polling interval?
3. How does NTP handle time drift?
4. How does NTP communicate?
5. What is the most accurate NTP server?
6. Should NTP load balance?
7. Does NTP need to be bidirectional?
8. How frequently does NTP update?
9. Should NTP be exposed to the Internet?
10. What is NTP security?
11. Does NTP use TCP or UDP?
12. Does NTP use SNMP?
13. Does NTP use TLS?
14. Is NTP always UTC?
15. Does NTP need DNS?
16. Does NTP use DNS?

What protocol is used for NTP?

NTP is a built-on UDP, where port 123 is used for NTP server communication and NTP clients use port 1023 (for example, a desktop).

What is the recommended NTP polling interval?

Resolution. NTP dynamically selects the optimal poll interval between the values of minpoll and maxpoll , which default to 64 and 1024 seconds respectively and are correct for most environments.

How does NTP handle time drift?

NTP (Network Time Protocol) is a daemon that makes small, innocuous changes to the server's clock to negate time drift. We also recommend you use the UTC time zone on everything (though we won't create a recommendation for this particular suggestion).

How does NTP communicate?

The clients and server communicate in a series of requests and responses: The client sends an NTP request packet to the time server, stamping the time as it does so (the origin timestamp). The server stamps the time when the request packet is received (the receive timestamp).

What is the most accurate NTP server?

As detailed at NTP.org, NTP works in a hierarchical fashion by passing time from one stratum to another. For example, Stratum 0 serves as a reference clock and is the most accurate and highest precision time server (e.g., atomic clocks, GPS clocks, and radio clocks.)

Should NTP load balance?

Load balancing NTP doesn't make sense, and can do more harm than good. RFC8633 (NTP Best Current Practice) has a section on anycast, and the same considerations apply to load balancers. If you have only one public IP address, expose just one stratum 2 server to the pool.

Does NTP need to be bidirectional?

NTP is highly scalable: A synchronization network may consist of several reference clocks. Each node of such a network can exchange time information either bidirectional or unidirectional.

How frequently does NTP update?

The NTP daemon checks the time servers periodically and adjusts the system clock to account for any drift between the local clock and the reference server (by default, somewhere between every 1 to 17 minutes).

Should NTP be exposed to the Internet?

If you do need to run NTP externally, only let it talk to specific hosts/networks. Cloud providers should keep up the great work by only exposing as much NTP as they need to and offering guidance to customers for how to run NTP securely (off the internet).

What is NTP security?

The use of authentication mechanisms in Network Time Protocol (NTP) is important to prevent the manipulation of time information by an attacker. The Symmetric Key based method and the Autokey approach are such mechanisms that have been around for many years.

Does NTP use TCP or UDP?

NTP uses UDP (User Data-gram Protocol) over TCP / IP. NTP messages are communicated using UDP port 23, which is reserved for the exclusive use of NTP traffic.

Does NTP use SNMP?

The SNMP agent communicates with the NTP server using NTP. To reduce the load imposed on the NTP server because of this communication, our implementation uses a caching mechanism to store some of the variables for short periods of time in the SNMP agent.

Does NTP use TLS?

In a nutshell, the NTS protocol is divided into two-phases. The first phase is the NTS key exchange that establishes the necessary key material between the NTP client and the server. This phase uses the Transport Layer Security (TLS) handshake and relies on the same public key infrastructure as the web.

Is NTP always UTC?

NTP always operates using UTC time rather than local time. It knows nothing of time zones and daylight saving. UTC time is pretty much the same as GMT time. It is the same all around the world and is unaffected by time zones or daylight saving time.

Does NTP need DNS?

To use NTP, your device configuration must allow DNS. DNS is allowed in the default configuration by the Outgoing policy. You must also configure DNS servers for the external interface before you enable NTP. For more information about how to configure DNS servers, see Add WINS and DNS Server Addresses.

Does NTP use DNS?

As mentioned earlier, the NTP pool uses DNS polling based on the pool subdomain to provide the required server IP to the client. DNSMon can measure the efficiency of its DNS polling by counting the DNS Record Set (RRset) frequency of A/AAAA records in the DNS.