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Questions tagged [ntp]

Network Time Protocol is an application level network protocol that is used for synchronizing clocks of computer systems. The term also refers to the reference software implementation.

The Network Time Protocol version 4 is defined in RFC 5905, RFC 5906, RFC 5907, and RFC 5908. NTPv4 is also suitable for the Internet Protocol version 6 address family.

The reference software implementation is provided by the NTP Public Services Project.

http://en.wikipedia.org/wiki/Network_Time_Protocol

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Keep time in sync among servers without internet connection

I have 5 servers on a LAN without Internet connection. I need them to keep the clock in sync among them. I could configure them as NTP peers, and set a high stratum for the local clock of one of them. In this way, the other four would sync with that…
cavedon
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NTP Request Packet

I'm trying to figure out what I need to send (client) in the NTP request package to retrieve a NTP package from the server. I'm working with the LWIP on Cortex M3, Stellaris LM3S6965 I understand that I will recieve a UDP header and then the NTP…
Sharpless512
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IOS receiving data timeout CFsocket

I want to connect with pool.ntp.org to time sync. So am creating a socket sock=CFSocketCreate(NULL, PF_INET, SOCK_DGRAM, IPPROTO_UDP, kCFSocketDataCallBack|kCFSocketWriteCallBack|kCFSocketConnectCallBack, sockCallback, &sock_ctx); then am…
tspentzas
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How can I access NTP clock in java

I have a distributed program written in java. I want my nodes access a synchronized physical clock. I know NTP is a protocol for physical clock synchronization. I know that I can install it on linux by sudo apt-get ntp. My question is when I…
Mohammad Roohitavaf
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Security group for AWS NTP Server

I just try to synchronize time with NTP-Server on EC2 instances: server 0.amazon.pool.ntp.org iburst server 1.amazon.pool.ntp.org iburst server 2.amazon.pool.ntp.org iburst server 3.amazon.pool.ntp.org iburst Unfortunately, I couldn't sync…
Toan Dao
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How to convert NTP time to Unix Epoch time in C language (Linux)

I have been trying for several months to create a simple SNTP single Client/Server based on RFC5905. Finally I manage to make it work at least I think it works correctly, but when I tried to test my code against a real NTP server (e.g.…
Thanos
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no server suitable for synchronization found For NTP Service

I had to build ntp packages from the source and install all of them on some hosts. After the installation, ntpdate 1.us.pool.ntp.org works for the synchronization. However, when I tried to do ntpdate it shows me the…
user3354832
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How does NTP Clock Discipline work?

I was reading NTPv4 rfc to better understand the mechanism used by ntp. So, far the basic idea seems to be simple. But I am a bit confused regarding how NTP Clock Discipline works. In NTPv4 it says a hybrid PLL/FLL is used to discipline the clock.…
fadedreamz
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Is there any C/C++ library to connect with a remote NTP server?

I'm making a C++ software that needs to syncronize system clock with remote NTP server. For now, I'm ussing "system" command to call the console "ntpdate" command. ..But I think is an ugly way to do that. Do you know any library that let me connect…
César Ortiz
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How to Generate Network Packets with C/C++

I want to generate a network packet to send over (for example) port 123 to an NTP server so I can receive and parse the returned packet. The goal is to better understand how packets are generated, read, and replied to by networked systems. (1)…
shelladept
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What is the purpose of the Root Delay field in the NTP protocol?

It's about the Network Time Protocol, specified in RFC 5905. I understand that the Root Delay field of NTPv4 packets (or the Synchronizing Distance field, as it is named in the previous version NTPv3) is a number indicating the estimated roundtrip…
Reflection
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How to Programmatically Set GPO to Not Configured or Disabled

I'm looking for a programmatic solution that has the same effect as setting the "Configure Windows NTP Client" state in GPOE Administrative Templates > System > Windows Time Service > Time Providers > Configure Windows NTP Client to Not Configured…
clover10
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Basic NTP Client in Windows in Visual C++

Good day, I am attempting to implement a very basic NTP client just so I can query a remote NTP server (ie: pool.ntp.org) for the internet time to automatically set the time on my Windows development board on each boot. I've refactored the code here…
Cloud
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Converting between NTP and C# DateTime

I use the following code to convert between NTP and a C# DateTime. I think the forward corversion is correct, but backwards is wrong. See the following code to convert 8 bytes into a DatTime: Convert NTP to DateTime public static ulong…
Andreas
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Epoch Seconds to Date Conversion on a Limited Embedded Device

I am trying to figure out the best way to convert from epoch seconds (since NTP epoch 1900-01-01 00:00) to a datetime string (MM/DD/YY,hh:mm:ss) without any libraries/modules/external functions, as they are not available on an embedded device. My…
swolpert
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