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 Startup Analysis - Rahul

• Student: RahulKatare
• Mentors: HarlanStenn, MartinBurnicki
• GSoC: GSoC Project Page

Summary

Ntpd program is an operating system daemon which sets and maintains system time of the day in synchronism with internet standard time servers. It operates by exchanging one or more messages with one or more configured servers at designated poll intervals. Ntpd currently applies small corrections (-500, 0 or 500 ppm discrete corrections) to the system time every second. If ntpd uses adjtime(), it updates the system clock every second. But some clock implementations do not provide small update to system clock. So there is a clock model which provides a kernel discipline called ntp_adjtime() which is used by Ntpd to adjust several parameters of the clock. There are two aspects to time corrections, applying an offset and adjusting the clock-frequency. The idea here is to perform a startup analysis of the time offset and the frequency correction that needs to be applied. The objective is to, first collect the data from N servers, using that calculate the offset and frequency adjustment that needs to be done.

Related Items: RFC 1589, http://www.ntp.org/ntpfaq/NTP-s-algo-kernel.htm

Tasks

• Project Design
• Framework
• Collecting Data from Single Host(Already done in the current code) and Analyzing it.
• Calculating slope and offset from the data and applying the correction to the clock and observing the effect.
• Collecting Data from Multiple Hosts.
• Exploring techniques to analyze data from multiple hosts.
• Test on both wired and wireless connections.

Timeline

Date	Task	Description	% Done
05-27	Community Bonding	Students get to know mentors, read documentation, get up to speed to begin working on their projects.
06-17	Coding Begins	Students begin coding for their GSoC projects
07-01	Lookup of existing code	Understanding the current code
07-27	Will be Away	Will be Travelling from home to my institute
07-29	BO Midterm Evals	Mentors and students can begin submitting mid-term evaluations.
08-02	EO Midterm Evals	Mid-term evaluations deadline.
09-16	Wrap-up	Suggested "Pencils Down" date. Take a week to scrub code, write tests, improve documentation, etc.
09-23	Firm "Pencils Down"	Mentors, students and organization administrators can begin submitting final evaluations to Google.
09-27	Final Evaluation	Final Evaluations Deadline
09-27	Code Samples	Students begin uploading code samples
10-01	Final Results	Final Results Announced

Discussion and Comments

Rahul, on 7/26 will your travels only take 1 day?

-- HarlanStenn - 2013-06-18

Yes, I'll be travelling for a day.

-- RahulKatare - 2013-06-23

Change of plans, will be travelliing on 7/27 for a day.

-- RahulKatare - 2013-07-13