NTP users are strongly urged to take immediate action to ensure that their NTP daemons are not susceptible to being used in distributed denial-of-service (DDoS) attacks. Please also take this opportunity to defeat denial-of-service attacks by implementing Ingress and Egress filtering through BCP38.

ntp-4.2.8p15 was released on 23 June 2020. It addresses 1 medium-severity security issue in ntpd, and provides 13 non-security bugfixes over 4.2.8p13.

Please see the NTP Security Notice for vulnerability and mitigation details.

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Are you using Autokey in production? If so, please contact Harlan - he's got some questions for you.

Clock Models (GSoC 2012)

• Student: ThiagodeFreitas
• Mentors: JudahLevine, HarlanStenn
• GSoC: GSoC Project Page

Summary

The goal of this project is to analyze the usefulness of different clock models for NTP, contributing for an enhanced performance. The goal is to use filtering techniques to analyze 2 issues. The first is a parameter that provides an explicit connection between the polling interval and the accuracy of the synchronization process. The second issue is a more sophisticated model for the performance of the clock on the local system and for the network delay.

Related Items: ClockAlgorithms

Repository

Current Code may be obtained at :

https://github.com/thiagodefreitas/NetworkTime

Tasks

1. Write a program that computes the Allan deviation of a local clock using the NTP data as the time differences. The NTP data would not adjust the local clock, so that the result would be the statistical performance of the combination.
2. Graphical representation of the data.
3. Run the estimator for about a week.
4. GUI Development
5. Calculate the Allan Deviation, the Histograms, the Residuals
6. Eliminate Bad-Measurements using the Allan Deviation of the Middle of the Data
7. Dr. Levine algorithm for eliminating outliers
8. Ransac algorithm for eliminating outliers
9. Allan Deviation of the corrected sampled data
10. Explanation of the results obtained. Small Report to Dr. Levine

Timeline

Date	Task	Description	% Done
04-23	Community Bonding	Students get to know mentors, read documentation, get up to speed to begin working on their projects.
05-21	Coding Begins	Students begin coding for their GSoC projects
05-22	1	Code the program proposed by Dr. Levine
05-28	2 and 3	Run the estimator for one week
06-09	4
06-15	5
06-23	6
07-09	BO Midterm Evals	Mentors and students can begin submitting mid-term evaluations.
07-13	EO Midterm Evals	Mid-term evaluations deadline.
07-21	7
07-28	8
08-04	9
08-15	10
08-13	Wrap-up	Suggested "Pencils Down" date. Take a week to scrub code, write tests, improve documentation, etc.
08-20	Firm "Pencils Down"	Mentors, students and organization administrators can begin submitting final evaluations to Google.
08-24	Final Evaluation	Final Evaluations Deadline
08-27	Final Results	Final Results Announced
08-31	Code Samples	Students begin uploading code samples

Discussion and Comments