What ntp servers should i use

There are a large number of public NTP time servers available across the Internet. Here we aim to provide an insight into available network time servers, configuring your client and synchronization best practices. The NTP pool project has been around for some time. The project provides Internet access to very large virtual clusters of NTP servers. The time servers that make up the pools are volunteered and made public by individuals or enterprises that have servers on the internet.

Pools of servers are located in most countries around the world. This allows clients to utilize a server that is relatively close, reducing round-trip delays and improving integrity.

The project is a subscription free service that is used world-wide by thousands of clients. Many computer systems and network devices are configured by default to synchronize to their time servers. You can also use the prefix 0, 1 or 2 to specify different pools of servers, if multiple server names are required:.

Almost every continent has a large number of clustered NTP time servers available. Including as of , Europe at , North America at , Asia at , Oceania at , making up a grand total of servers. Again, for each of these zones, you can specify a 0, 1 or 2 prefix if multiple server names are required. For instance:. Let's say the record for north-america. Simple example, ping north-america. Then ping it again, it will have same IP because the record is cached.

Or, get your own NTP server, inside your network. GPS-referenced, or not. With better ones, you can point to the pool as a backup. It's not that hard, and where security or compliance are at issue, fairly easy to cost-justify. To continue this discussion, please ask a new question. Which of the following retains the information it's storing when the system power is turned off?

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As administrator enter. This will work on Windows and newer. If you use an older version of windows you can try.

Meinberg made a port of the ntp daemon for windows. If your Windows system is part of a domain, you might not be able to independently update your computer time. Consider if the NTP Pool is appropriate for your use.

If business, organization or human life depends on having correct time or can be harmed by it being wrong, you shouldn't "just get it off the internet". The NTP Pool is generally very high quality, but it is a service run by volunteers in their spare time. Please talk to your equipment and service vendors about getting local and reliable service setup for you.

For example, a replay attack can occur when a user attempts to provide proof of identity to another user. A malicious actor in the middle would intercept the message and prevent it from getting to its intended target.

The malicious user then sends a request for identity confirmation and includes the stolen proof as a validation. If the time is not synchronized, the window that the exchange is allowed can be increased beyond what is considered safe and allows the subterfuge.

As a result, valid users can be tricked into thinking that they have successfully confirmed the identity of an imposter posing as a legitimate user. In all fairness, this type of replay attack is uncommon and extremely challenging to execute successfully without access to the network, the communications path, and a compromised machine in that path. Many security experts, such as Shaun Kelly , have noted that NTP has been used to manipulate logs and change the time on a computer system, altering the sequence of events.

When clocks aren't synchronized, network analysts have a much harder time performing log correlation across disparate systems. The manipulation of NTP can make the identification of network activities and sequence of events leading up to an attack much harder to pinpoint.

Other applications that would be at risk because time is not working right include high-speed trading and security cameras. Many time-sensitive encryption algorithms involving key exchanges and tokens are also at risk because of NTP weaknesses. The remainder of this post details best practices for configuring your own NTP server and requesting a public NTP server. Use Public NTP for external hosts. If an enterprise is building capabilities, services, or other embedded platforms that are intended to be deployed outside of the enterprise, network administrators might want to consider requesting a public NTP server from the pool of available servers mentioned earlier.

It's important to note that most of the public NTP servers specify rules of engagement. If an enterprise has multiple devices within the enterprise that will be using NTP, it would make sense to set up their own hierarchy to synchronize with instead of competing for access to the publicly available servers. Configure your own Internal NTP hierarchical service for your network. It is possible to purchase Stratum 1 or Stratum 0 NTP appliances to use internally for less than the cost of a typical server.

It is also possible to set up a private NTP server at a very low cost. If you do decide to configure you own, please consider the following best practices:. The presence of three or more time sources would allow the network to maintain accurate time even if one of the primary masters fails.

Ideally, NTP servers would be located in three geographically disparate locations.