Ntp update frequency default

A properly running full NTP client will decide on its own how often to poll the servers you've configured. Initially it will probably check every 64 seconds, but once the clock has been stabilized, the polling may be every s there's a doubling in the algorithm at every step. If the algorithm detects something wonky with the clock it will automatically start polling more often as needed.

If you absolutely, positively need accurate time, use the full NTP. Because so much is dependent on the time service you can very easily get your fingers burned.

Having said that, if you really want to change things, you should have a look at this KB article for further guidance. Just make a simple script with one string and config Windows task manager to run it as often as you need. Create text document; Write script line: net time - update time command; Save file; Change extension from.

By net time command your can also set NTP-servers from where you want to update By default system one is used. More info by net time?

Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Asked 11 years, 11 months ago. The event message code and message field are described on the "Event Messages and Status Words" page. Enables recording of peer statistics information.

This includes statistics records of all peers of an NTP server and of special signals, where present and configured. Each valid update appends a line of the following form to the current element of a file generation set named peerstats :.

The third field shows the reference clock type and unit number but if you are running in the peer address in dotted-quad notation instead The fourth field is a status word, encoded in hex in the format described in Appendix A of the NTP specification RFC The final four fields show the offset, delay, dispersion and RMS jitter, all in seconds. Enables recording of raw-timestamp statistics information.

Each NTP message received from a peer or clock driver appends a line of the following form to the file generation set named rawstats :. The next two fields show the remote peer or clock identification followed by the local address in dotted-quad notation.

The final four fields show the originate, receive, transmit and final NTP timestamps in order. The timestamp values are as received and before processing by the various data smoothing and mitigation algorithms. Enables recording of ntpd statistics counters on a periodic basis.

Each hour a line of the following form is appended to the file generation set named sysstats :. The remaining ten fields show the statistics counter values accumulated since the last generated line.

Enables recording of ntpd resource usage statistics. Each hour a line of the following form is appended to the file generation set named usestats :. See man getrusage for details. The maxrss column is the high water mark since the process was started. The remaining fields show the values used since the last report. Indicates the full path of a directory where statistics files should be created see below.

This keyword allows the otherwise constant filegen filename prefix to be modified for file generation sets, which is useful for handling statistics logs. Configures setting of the generation file set name. Generation file sets provide a means for handling files that are continuously growing during the lifetime of a server.

Server statistics are a typical example for such files. Generation file sets provide access to a set of files used to store the actual data.

At any time at most one element of the set is being written to. The type given specifies when and how data will be directed to a new element of the set. This way, information stored in elements of a file set that are currently unused are available for administrative operations without the risk of disturbing the operation of ntpd.

Most important: they can be removed to free space for new data produced. This is the file name for the statistics records. Filenames of set members are built from three concatenated elements prefix , filename and suffix :.

This is a constant filename path. It is not subject to modifications via the filegen option. It is defined by the server, usually specified as a compile-time constant. It may, however, be configurable for individual file generation sets via other commands. For example, the prefix used with loopstats and peerstats generation can be configured using the statsdir option explained above. This can be modified using the file argument to the filegen statement.

This part is reflects individual elements of a file set. It is generated according to the type of a file set. A file generation set is characterized by its type. One element of file set is used per incarnation of a ntpd server. This type does not perform any changes to file set members during runtime, however it provides an easy way of separating files belonging to different ntpd 8 server incarnations.

One file generation set element is created per day. A day is defined as the period between and UTC. YYYY is a 4-digit year number e. MM is a two digit month number. Thus, all information written at 10 December would end up in a file named prefix filename.

Any file set member contains data related to a certain week of a year. The term week is defined by computing day-of-year modulo 7. Elements of such a file generation set are distinguished by appending the following suffix to the file set filename base: A dot, a 4-digit year number, the letter W , and a 2-digit week number.

For example, information from January, 10th would end up in a file with suffix W1. One generation file set element is generated per month. The file name suffix consists of a dot, a 4-digit year number, and a 2-digit month.

One generation file element is generated per year. The filename suffix consists of a dot and a 4 digit year number. This type of file generation sets changes to a new element of the file set every 24 hours of server operation. The filename suffix consists of a dot, the letter a , and an 8-digit number. This number is taken to be the number of seconds the server is running at the start of the corresponding hour period.

It is convenient to be able to access the current element of a file generation set by a fixed name. This feature is enabled by specifying link and disabled using nolink. If link is specified, a hard link from the current file set element to a file without suffix is created.

When there is already a file with this name and the number of links of this file is one, it is renamed appending a dot, the letter C , and the pid of the ntpd server process. When the number of links is greater than one, the file is unlinked. This allows the current file to be accessed by a constant name. Enables or disables the recording function. Information is only written to a file generation by specifying enable ; output is prevented by specifying disable.

A match occurs when the bitwise AND of the mask and the packet source address is equal to the bitwise AND of the mask and address in the list. The list is searched in order with the last match found defining the restriction flags associated with the entry.

The restriction facility was implemented in conformance with the access policies for the original NSFnet backbone time servers. Later the facility was expanded to deflect cryptographic and clogging attacks. While this facility may be useful for keeping unwanted or broken or malicious clients from congesting innocent servers, it should not be considered an alternative to the NTP authentication facilities.

Source address based restrictions are easily circumvented by a determined cracker. Clients can be denied service because they are explicitly included in the restrict list created by the restrict command or implicitly as the result of cryptographic or rate limit violations.

Cryptographic violations include certificate or identity verification failures; rate limit violations generally result from defective NTP implementations that send packets at abusive rates. Some violations cause denied service only for the offending packet, others cause denied service for a timed period and others cause the denied service for an indefinite period. When a client or network is denied access for an indefinite period, the only way at present to remove the restrictions is by restarting the server.

Ordinarily, packets denied service are simply dropped with no further action except incrementing statistics counters. Sometimes a more proactive response is needed, such as a server message that explicitly requests the client to stop sending and leave a message for the system operator. A special packet format has been created for this purpose called the "kiss-of-death" KoD packet. KoD packets have the leap bits set unsynchronized and stratum set to zero and the reference identifier field set to a four-byte ASCII code.

If the noserve or notrust flag of the matching restrict list entry is set, the code is "DENY"; if the limited flag is set and the rate limit is exceeded, the code is "RATE". Finally, if a cryptographic violation occurs, the code is "CRYP". A client receiving a KoD performs a set of sanity checks to minimize security exposure, then updates the stratum and reference identifier peer variables, sets the access denied BOGON4 bit in the peer flash variable and sends a message to the log.

The only way at present to recover from this condition is to restart the protocol at both the client and server. This happens automatically at the client when the association times out.

It will happen at the server only if the server operator cooperates. Set the parameters of the limited facility which protects the server from client abuse. Internally, each MRU slot contains a score in units of packets per second.

It is updated each time a packet arrives from that IP Address. The score decays exponentially at the burst rate and is bumped by 1. Specify the allowed burst size if the bursts are far enough apart to keep the average rate below average.

The default is The address argument expressed in dotted-quad for IPv4 or :-delimited for IPv6 form is the address of a host or network. Alternatively, the address argument can be a valid host DNS name. The mask argument expressed in IPv4 or IPv6 numeric address form defaults to all mask bits on, meaning that the address is treated as the address of an individual host. A default entry address 0. Note that text string default , with no mask option, may be used to indicate the default entry.

In the current implementation, flag always restricts access, i. The flags are not orthogonal, in that more restrictive flags will often make less restrictive ones redundant. The flags can generally be classed into two categories, those which restrict time service and those which restrict informational queries and attempts to do a run-time reconfiguration of the server.

One or more of the following flags may be specified:. For example, maxpoll 9 indicates that the polling interval should stay at or below 9 seconds. Example: server myntpserver. Log in to comment. JS Community Member 26 points. Jonathan Seigler. Does this also work for Rhel 7. Here are the common uses of Markdown.

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Learn more. At what time intervals does ntpd update the time? Ask Question. Asked 5 years, 6 months ago. Active 3 years, 1 month ago. Viewed 23k times. I'm running the latest ntpd. After synchronizing I changed my system time manually using date command date -s ' ' My system time got changed as per the date command. Improve this question.