1.1. Build and Install

You have come here because you found a cryptic message in the system log. This page by no means lists all messages that might be found, since new ones come and old ones go. Generally, however, the most common ones will be found here. They are listed by program module and log severity code in bold: LOG_ERR, LOG_NOTICE and LOG_INFO.

Most of the time LOG_ERR messages are fatal, but often ntpd limps onward in the hopes of discovering more errors. The LOG_NOTICE messages usually mean the time has changed or some other condition that probably should be noticed. The LOG_INFO messages usually say something about the system operations, but do not affect the time.

In the following a '?' character stands for text in the message. The meaning should be clear from context.

2. Protocol Module

2.1. LOG_ERR

buffer overflow ?

Fatal error. An input packet is too long for processing.


no reply; clock not set

No servers have been found. The server(s) and/or network may be down. Standard debugging procedures apply.


proto_config: illegal item ?, value ?

Program error. Bugs can be reported here.

receive: server server maximum rate exceeded

A kiss-o’death packet has been received. The transmit rate is automatically reduced.

pps sync enabled

The PPS signal has been detected and enabled.

transmit: encryption key ? not found

The encryption key is not defined or not trusted.

precision = ? usec

This reports the precision measured for this machine.

using 10ms tick adjustments

Gotcha for some machines with dirty rotten clock hardware.

no servers reachable

The system clock is running on internal batteries. The server(s) and/or network may be down.

3. Clock Discipline Module

3.1. LOG_ERR

time correction of ? seconds exceeds sanity limit (?); set clock manually to the correct UTC time.

Fatal error. Better do what it says, then restart the daemon. Be advised NTP and Unix know nothing about local time zones. The clock must be set to Coordinated Universal Time (UTC). Believe it; by international agreement abbreviations are in French and descriptions are in English.

sigaction() fails to save SIGSYS trap: ?
sigaction() fails to restore SIGSYS trap: ?
Program error. Bugs can be reported here.


frequency error ? exceeds tolerance 500 PPM

The hardware clock frequency error exceeds the rate the kernel can correct. This could be a hardware or a kernel problem.

time slew ? s

The time error exceeds the step threshold and is being slewed to the correct time. You may have to wait a very long time.

time reset ? s

The time error exceeds the step threshold and has been reset to the correct time. Computer scientists don’t like this, but they can set the ntpd -x option and wait forever.

kernel time sync disabled ?

The kernel reports an error. See the codes in the timex.h file.

pps sync disabled

The PPS signal has died, probably due to a dead radio, broken wire or loose connector.


kernel time sync status ?

For information only. See the codes in the timex.h file.

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