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Mastering pfSense

You're reading from   Mastering pfSense Manage, secure, and monitor your on-premise and cloud network with pfSense 2.4

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Product type Paperback
Published in May 2018
Publisher
ISBN-13 9781788993173
Length 450 pages
Edition 2nd Edition
Tools
Concepts
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Author (1):
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David Zientara David Zientara
Author Profile Icon David Zientara
David Zientara
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Table of Contents (15) Chapters Close

Preface 1. Revisiting pfSense Basics FREE CHAPTER 2. Advanced pfSense Configuration 3. VLANs 4. Using pfSense as a Firewall 5. Network Address Translation 6. Traffic Shaping 7. Virtual Private Networks 8. Redundancy and High Availability 9. Multiple WANs 10. Routing and Bridging 11. Extending pfSense with Packages 12. Diagnostics and Troubleshooting 13. Assessments 14. Another Book You May Enjoy

NTP

NTP is an application layer protocol that controls the synchronization of various devices over the internet to within a few milliseconds of Coordinated Universal Time (CUT). NTP is hierarchical, with servers organized into different strata. At stratum 0 are high-precision time devices such as atomic clocks. At stratum 1 are computers that are synchronized within a few microseconds to their directly connected stratum 0 devices. At stratum 2 are computers that are directly connected to stratum 1 computers, and so on. Synchronization is achieved by adjusting the system time based on an offset. The offset is calculated by taking an average of the differences of the timestamps on request and response packets between the client and the server. The clock frequency is then adjusted to reduce the offset gradually, and the newly adjusted clock provides timestamps for the next request...

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