What does Ntpdc command do?

What does Ntpdc command do?

The ntpdc command sends a query to the ntpd daemon running on each of the hosts listed on the command line. The ntpd daemon on each responding host sends information about the current calculated offset between its time and the time of each of its NTP servers or peers.

How do I know if NTP is synchronized?

The ntpstat command will report the synchronisation state of the NTP daemon running on the local machine….exit status of ntpstat command

1. If exit status 0 – Clock is synchronised.
2. exit status 1 – Clock is not synchronised.
3. exit status 2 – If clock state is indeterminant, for example if ntpd is not contactable.

What are NTP peers?

NTP peers are NTP clients that share a common NTP server. An NTP client that loses connection with an NTP server can synchronize the time with an NTP peer. NTP peers query each other to synchronize their clocks. An NTP peer that loses connection with another NTP peer loses all NTP synchronization.

What is offset and jitter in NTP?

The offset column refers to the delay in reaching the server, in milliseconds. Offset references the difference between the local clock and the server’s clock. Finally, the jitter column refers to the network latency between your server and theirs.

What is NTPQ command in Linux?

The ntpq command uses NTP mode 6 packets to communicate with the NTP server and can query any compatible server on the network which permits it. The ntpq command makes one attempt to retransmit requests, and will time-out requests if the remote host does not respond within a suitable time.

What happens when NTP is not synchronized?

When the clocks in a network fall out of sync – with each other or with the correct time – bad things start to happen. Processes fail. Data is lost. Security is compromised.

Is NTP a TCP or UDP?

UDP
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). Unfortunately, like many legacy protocols, NTP suffers from security issues.

What is NTP in Cisco?

Network Time Protocol (NTP) is a protocol designed to time-synchronize a network of machines. NTP runs on User Datagram Protocol (UDP), which in turn runs on IP. NTP Version 3 is documented in RFC 1305. This module describes how to configure Network Time Protocol on Cisco devices.

What is the default timeout for ntpdc queries?

Specify a timeout period for responses to server queries. The default is about 8000 milliseconds. Note that since ntpdc retries each query once after a timeout, the total waiting time for a timeout will be twice the timeout value set.

What is the operation of ntpdc?

The operation of ntpdc are specific to the particular implementation of the ntpd daemon and can be expected to work only with this and maybe some previous versions of the daemon.

Why do I need to authenticate a remote ntpdc program?

Requests from a remote ntpdc program which affect the state of the local server must be authenticated, which requires both the remote program and local server share a common key and key identifier.

Isntpdc a good program?

ntpdc is a crude hack. Much of the information it shows is deadly boring and could only be loved by its implementer. The program was designed so that new (and temporary) features were easy to hack in, at great expense to the program’s ease of use.