Attacking the Network Time Protocol
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Option 33: Dual Internal NTP Server Setup and Operation Guidelines
-DISCONTINUED PRODUCT- Option 33: Dual Internal NTP Server Setup and Operation Guidelines Document No. PD0042100D – April 2009 Arbiter Systems, Inc. 1324 Vendels Circle, Suite 121 Paso Robles, CA 93446 U.S.A. (805) 237-3831, (800) 321-3831 http://www.arbiter.com mailto: [email protected] 1 Option 33: Dual Internal NTP Server 1.1 General Description Option 33, Dual Internal Network Time Protocol (NTP) Server, is used in the Arbiter Systems line of 19-inch, rack mount Satellite-Controlled Clocks. This option comes with a six-foot phone cable and RJ-11 to DB-9F adapter for connecting to the RS-232, or NTP Setup, port. 1.1.1 Option 33 Option 33 allows the clock to act as time server over an Ethernet network using the network time protocol operating in server mode - symmetric operation modes are not supported. Time is distributed over the network interface to computers, controllers and other equipment needing the correct time. Option 33 understands NTP Version 1, Version 2, and Version 3 frames, and optionally supports authentication via DES and MD5 cryptographic checksums. If authentication is not used, the controller can typically be used for hundreds of clients without overloading it. Authentication requires typically 40 ms for checking and generating the cryptograms, which is covered and averaged out by the protocol. Option 33 supports full SNTP and all NTP functions required for reliable server operation. Functions not required for server operation are not implemented. 1.1.2 Hardware Configuration. Option 33 consists of two building blocks; two OEM NTP modules and an interface to the GPS clock. -
Netflix and Twitch Traffic Characterization
University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies The Vault: Electronic Theses and Dissertations 2015-09-30 NetFlix and Twitch Traffic Characterization Laterman, Michel Laterman, M. (2015). NetFlix and Twitch Traffic Characterization (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/27074 http://hdl.handle.net/11023/2562 master thesis University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca UNIVERSITY OF CALGARY NetFlix and Twitch Traffic Characterization by Michel Laterman A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE GRADUATE PROGRAM IN COMPUTER SCIENCE CALGARY, ALBERTA SEPTEMBER, 2015 c Michel Laterman 2015 Abstract Streaming video content is the largest contributor to inbound network traffic at the University of Calgary. Over five months, from December 2014 { April 2015, over 2.7 petabytes of traffic on 49 billion connections was observed. This thesis presents traffic characterizations for two large video streaming services, namely NetFlix and Twitch. These two services contribute a significant portion of inbound bytes. NetFlix provides TV series and movies on demand. Twitch offers live streaming of video game play. These services share many characteristics, including asymmetric connections, content delivery mechanisms, and content popularity patterns. -
Network Time Protocol (NTP) General Overview
Network Time Protocol (NTP) General Overview David L. Mills University of Delaware http://www.eecis.udel.edu/~mills mailto:[email protected] alautun, Maya glyph 2-Aug-04 1 Introduction z Network Time Protocol (NTP) synchronizes clocks of hosts and routers in the Internet. z NIST estimates 10-20 million NTP servers and clients deployed in the Internet and its tributaries all over the world. Every Windows/XP has an NTP client. z NTP provides nominal accuracies of low tens of milliseconds on WANs, submilliseconds on LANs, and submicroseconds using a precision time source such as a cesium oscillator or GPS receiver. z NTP software has been ported to almost every workstation and server platform available today - from PCs to Crays - Unix, Windows, VMS and embedded systems, even home routers. z The NTP architecture, protocol and algorithms have been evolved over the last two decades to the latest NTP Version 4 described in this and related briefings. 2-Aug-04 2 The Sun never sets on NTP z NTP is argueably the longest running, continuously operating, ubiquitously available protocol in the Internet – USNO and NIST, as well as equivalents in other countries, provide multiple NTP primary servers directly synchronized to national standard cesium clock ensembles and GPS – Over 230 Internet primary serversare in Australia, Canada, Chile, France, Germany, Isreal, Italy, Holland, Japan, Norway, Sweden, Switzerland, UK, and US. z Well over a million Internet servers and clients all over the world – National and regional service providers BBN, MCI, Sprint, Alternet, etc. – Agencies and organizations: US Weather Service, US Treasury Service, IRS, PBS, Merrill Lynch, Citicorp, GTE, Sun, DEC, HP, etc. -
Which Time Server Option Is Best for Synchronizing Your Clocks
WHICH TIME SERVER OPTION IS BEST FOR SYNCHRONIZING YOUR CLOCKS? Any electronic device that automatically displays REGARDING MASTER the current local time – your clocks, phone, tablet, TIME CONTROLLERS computer and even most TVs – has to pull that time from a time server. AND The time server acts as a messenger of sorts; IP NETWORK CLOCKS it reads the time from a reference clock and distributes that information via a computer network (ETHERNET OR WI-FI) to your device when the device requests it. The time server could be a local network time server or an internet time server. SNTP, or Simple Network Time Protocol, is an internet standard protocol that allows a clock or device to contact a server and get the current time. It’s a simplification of the more robustNTP (Network Time Protocol) and is used in most embedded devices and computers. Once the device receives the current Coordinated Universal Time (UTC), the device applies offsets such as time zone or daylight saving time considerations, as well as the time spent on the network retrieving the time, before displaying the accurate local time. January 2018 AMERICAN TIME WHITE PAPER BY: MAX BLOM When it comes to syncing time for your organization’s clocks, you have 3 options: Let’s take a look at how each of these options work, their pros and cons, and our recommendation. Port 123 is reserved specifically for External Server IP Address NTP/SNTP communication 1 The NIST – the U.S. Department of Commerce’s National Institute of Standards and Technology – is the primary source for synchronizing time systems in the U.S. -
Endrun TECHNOLOGIES Præcis Cntp Network Time Server
Smarter Timing Solutions EndRun TECHNOLOGIES Præcis Cntp Network Time Server User’s Manual Præcis Cntp Network Time Server User’s Manual EndRun Technologies 1360 North Dutton Avenue #200 Santa Rosa, California USA 95401 Phone 707-573-8633 • Fax 707-573-8619 Preface Thank you for purchasing the Præcis Cntp Network Time Server. Our goal in developing this product is to bring precise, Universal Coordinated Time (UTC) into your network quickly, easily and reliably. Your new Præcis Cntp is fabricated using the highest quality materials and manufacturing processes available today, and will give you years of troublefree service. About EndRun Technologies Founded in 1998 and headquartered in Santa Rosa, California, we are the leaders in the exciting new time and frequency distribution technology based on the Code Division Multiple Access (CDMA) mobile telecommunications infrastructure. Our innovative designs and painstaking attention to the details of efficient manufacturability have made us the first to bring this technology to the broad synchronization market at prices small businesses can afford. EndRun Technologies markets this technology in three major product lines: Network Time Sources/Servers – These units are configured for optimum performance in operation with network servers/networks running the Internet protocol known as the Network Time Protocol (NTP). Instrumentation Time and Frequency References – These products provide UTC traceable time and frequency signals for use in precision test and measurement instrumentation. OEM Time and Frequency Engines – These products provide the core time and frequency capabilities to our customers who require lower cost and tighter integration with their own products. About this manual This manual will guide you through simple installation and set up procedures. -
Computer Networks
Computer Networks 4/6/21 Computer Networks 1 Circuit and Packet Switching • Circuit switching • Packet switching – Legacy phone network – Internet – Single route through – Data split into packets sequence of hardware – Packets transported devices established when independently through two nodes start network communication – Each packet handled on a – Data sent along route best efforts basis – Route maintained until – Packets may follow communication ends different routes 4/6/21 Computer Networks 2 Packet Switching B F 3 2 1 A D C E 4/6/21 Computer Networks 3 Packet Switching B F 1 3 2 A D C E 4/6/21 Computer Networks 4 Packet Switching B F 1 2 3 A D C E 4/6/21 Computer Networks 5 Packet Switching B F 1 2 3 A D C E 4/6/21 Computer Networks 6 Protocols • A protocol defines the rules for communication between computers • Protocols are broadly classified as connectionless and connection oriented • Connectionless protocol – Sends data out as soon as there is enough data to be transmitted – E.g., user datagram protocol (UDP) • Connection-oriented protocol – Provides a reliable connection stream between two nodes – Consists of set up, transmission, and tear down phases – Creates virtual circuit-switched network – E.g., transmission control protocol (TCP) 4/6/21 Computer Networks 7 Encapsulation • A packet typically consists of – Control information for addressing the packet: header and footer – Data: payload • A network protocol N1 can use the services of another network protocol N2 – A packet p1 of N1 is encapsulated into a packet p2 of N2 -
Networkingsimple Network Time Protocol
IBM i Version 7.2 Networking Simple Network Time Protocol IBM Note Before using this information and the product it supports, read the information in “Notices” on page 11. This document may contain references to Licensed Internal Code. Licensed Internal Code is Machine Code and is licensed to you under the terms of the IBM License Agreement for Machine Code. © Copyright International Business Machines Corporation 1998, 2013. US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Simple Network Time Protocol...............................................................................1 PDF file for Simple Network Time Protocol.................................................................................................1 SNTP concepts............................................................................................................................................. 1 SNTP client............................................................................................................................................. 2 SNTP server............................................................................................................................................ 2 Scenario: Synchronizing clocks with IBM i..................................................................................................3 Configuring System A as an SNTP client and server..............................................................................5 Configuring -
NBAR2 Standard Protocol Pack 1.0
NBAR2 Standard Protocol Pack 1.0 Americas Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 527-0883 © 2013 Cisco Systems, Inc. All rights reserved. CONTENTS CHAPTER 1 Release Notes for NBAR2 Standard Protocol Pack 1.0 1 CHAPTER 2 BGP 3 BITTORRENT 6 CITRIX 7 DHCP 8 DIRECTCONNECT 9 DNS 10 EDONKEY 11 EGP 12 EIGRP 13 EXCHANGE 14 FASTTRACK 15 FINGER 16 FTP 17 GNUTELLA 18 GOPHER 19 GRE 20 H323 21 HTTP 22 ICMP 23 IMAP 24 IPINIP 25 IPV6-ICMP 26 IRC 27 KAZAA2 28 KERBEROS 29 L2TP 30 NBAR2 Standard Protocol Pack 1.0 iii Contents LDAP 31 MGCP 32 NETBIOS 33 NETSHOW 34 NFS 35 NNTP 36 NOTES 37 NTP 38 OSPF 39 POP3 40 PPTP 41 PRINTER 42 RIP 43 RTCP 44 RTP 45 RTSP 46 SAP 47 SECURE-FTP 48 SECURE-HTTP 49 SECURE-IMAP 50 SECURE-IRC 51 SECURE-LDAP 52 SECURE-NNTP 53 SECURE-POP3 54 SECURE-TELNET 55 SIP 56 SKINNY 57 SKYPE 58 SMTP 59 SNMP 60 SOCKS 61 SQLNET 62 SQLSERVER 63 SSH 64 STREAMWORK 65 NBAR2 Standard Protocol Pack 1.0 iv Contents SUNRPC 66 SYSLOG 67 TELNET 68 TFTP 69 VDOLIVE 70 WINMX 71 NBAR2 Standard Protocol Pack 1.0 v Contents NBAR2 Standard Protocol Pack 1.0 vi CHAPTER 1 Release Notes for NBAR2 Standard Protocol Pack 1.0 NBAR2 Standard Protocol Pack Overview The Network Based Application Recognition (NBAR2) Standard Protocol Pack 1.0 is provided as the base protocol pack with an unlicensed Cisco image on a device. -
New Milestone in Network Time Security As Internet Draft Approved
New milestone in Network Time Security as Internet Draft approved Stockholm, Sweden - 27 March 2020- Netnod, a leading provider of interconnection and DNS services, is pleased to announce that the Internet Draft ‘Network Time Security for the Network Time Protocol’ has been approved as a Proposed Standard. The approval came from the Internet Engineering Steering Group (IESG) on 25 March during the virtual IETF meeting. Netnod staff have been instrumental in developing this protocol which adds a much needed layer of security to the Network Time Protocol (NTP) and follows from Netnod’s launch of one of the first NTS-enabled NTP services in October 2019. The new standard (https://tools.ietf.org/html/draft-ietf-ntp-using-nts-for-ntp-28) adds an important layer of security to NTP in a similar way that Transport Layer Security (TLS) adds security to the Hypertext Transfer Protocol (HTTP), which users can see in their web browsers as a closed padlock. As described in the Proposed Standard, NTS is: ”a mechanism for using Transport Layer Security (TLS) and Authenticated Encryption with Associated Data (AEAD) to provide cryptographic security for the client-server mode of the Network Time Protocol (NTP).” NTP, the most popular protocol in use for synchronizing time, is more than 30 years old and vulnerable to Man-in-the-Middle (MITM) attacks. With many of today’s most important security processes dependent on accurate time, the consequences of receiving time from a malicious source are serious. Everything from establishing encrypted TLS sessions and using DNSSEC to time-stamping financial transactions and preventing online fraud depends on accurate and secure time. -
(ARP): Spoofing Attack and Proposed Defense
Communications and Network, 2016, 8, 118-130 Published Online August 2016 in SciRes. http://www.scirp.org/journal/cn http://dx.doi.org/10.4236/cn.2016.83012 Address Resolution Protocol (ARP): Spoofing Attack and Proposed Defense Ghazi Al Sukkar1, Ramzi Saifan2, Sufian Khwaldeh3, Mahmoud Maqableh4, Iyad Jafar2 1Electrical Engineering Department, The University of Jordan, Amman, Jordan 2Computer Engineering Department, The University of Jordan, Amman, Jordan 3Business Information Technology Department, The University of Jordan, Amman, Jordan 4Management Information Systems Department, The University of Jordan, Amman, Jordan Received 7 May 2016; accepted 11 July 2016; published 14 July 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Networks have become an integral part of today’s world. The ease of deployment, low-cost and high data rates have contributed significantly to their popularity. There are many protocols that are tailored to ease the process of establishing these networks. Nevertheless, security-wise pre- cautions were not taken in some of them. In this paper, we expose some of the vulnerability that exists in a commonly and widely used network protocol, the Address Resolution Protocol (ARP) protocol. Effectively, we will implement a user friendly and an easy-to-use tool that exploits the weaknesses of this protocol to deceive a victim’s machine and a router through creating a sort of Man-in-the-Middle (MITM) attack. In MITM, all of the data going out or to the victim machine will pass first through the attacker’s machine. -
Securing ARP and DHCP for Mitigating Link Layer Attacks
Sa¯dhana¯ Vol. 42, No. 12, December 2017, pp. 2041–2053 Ó Indian Academy of Sciences https://doi.org/10.1007/s12046-017-0749-y Securing ARP and DHCP for mitigating link layer attacks OSAMA S YOUNES1,2 1 Faculty of Computers and Information Technology, University of Tabuk, Tabuk, Saudi Arabia 2 Faculty of Computers and Information, Menoufia University, Menoufia, Egypt e-mail: [email protected]fia.edu.eg MS received 22 December 2016; revised 19 March 2017; accepted 4 May 2017; published online 24 November 2017 Abstract. Network security has become a concern with the rapid growth and expansion of the Internet. While there are several ways to provide security for communications at the application, transport, or network layers, the data link layer security has not yet been adequately addressed. Dynamic Host Configuration Protocol (DHCP) and Address Resolution Protocol (ARP) are link layer protocols that are essential for network operation. They were designed without any security features. Therefore, they are vulnerable to a number of attacks such as the rogue DHCP server, DHCP starvation, host impersonation, man-in-the-middle, and denial of service attacks. Vulnerabilities in ARP and DHCP threaten the operation of any network. The existing solutions to secure ARP and DHCP could not mitigate DHCP starvation and host impersonation attacks. This work introduces a new solution to secure ARP and DHCP for preventing and mitigating these LAN attacks. The proposed solution provides integrity and authenticity for ARP and DHCP messages. Security properties and performance of the proposed schemes are investigated and compared to other related schemes. -
IBM Z Server Time Protocol Guide
Front cover Draft Document for Review August 3, 2020 1:37 pm SG24-8480-00 IBM Z Server Time Protocol Guide Octavian Lascu Franco Pinto Gatto Gobehi Hans-Peter Eckam Jeremy Koch Martin Söllig Sebastian Zimmermann Steve Guendert Redbooks Draft Document for Review August 3, 2020 7:26 pm 8480edno.fm IBM Redbooks IBM Z Server Time Protocol Guide August 2020 SG24-8480-00 8480edno.fm Draft Document for Review August 3, 2020 7:26 pm Note: Before using this information and the product it supports, read the information in “Notices” on page vii. First Edition (August 2020) This edition applies to IBM Server Time Protocol for IBM Z and covers IBM z15, IBM z14, and IBM z13 server generations. This document was created or updated on August 3, 2020. © Copyright International Business Machines Corporation 2020. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Draft Document for Review August 3, 2020 8:32 pm 8480TOC.fm Contents Notices . vii Trademarks . viii Preface . ix Authors. ix Comments welcome. .x Stay connected to IBM Redbooks . xi Chapter 1. Introduction to Server Time Protocol . 1 1.1 Introduction to time synchronization . 2 1.1.1 Insertion of leap seconds . 2 1.1.2 Time-of-Day (TOD) Clock . 3 1.1.3 Industry requirements . 4 1.1.4 Time synchronization in a Parallel Sysplex. 6 1.2 Overview of Server Time Protocol (STP) . 7 1.3 STP concepts and terminology . 9 1.3.1 STP facility . 9 1.3.2 TOD clock synchronization .