update chapter ntp

This commit is contained in:
chhan11 2017-06-02 03:18:30 +02:00
parent 1c1549851d
commit 3660cde6f2
4 changed files with 34 additions and 10 deletions

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@ -20,22 +20,25 @@
\newacronym{dhcp}{DHCP}{Dynamic Host Control Protocol}
\newacronym{dknog}{DKNOG}{Danish Network Operators' Group}
\newacronym{dns}{DNS}{Domain Name System}
\newacronym{dst}{DST}{Destination}
\newacronym{dst}{dst}{destination}
\newacronym{dwdm}{DWDM}{}
\newacronym{eap}{EAP}{Extensible Authentication Protocol}
\newacronym{eapol}{EAPOL}{Extensible Authentication Protocol over Local Area Network}
\newacronym{eapol}{EAPoL}{Extensible Authentication Protocol over Local Area Network}
\newacronym{eigrp}{EIGRP}{Enhanced Interior Gateway Routing Protocol}
\newacronym{evpn}{EVPN}{Ethernet Virtual Private Network}
\newacronym{ftp}{FTP}{File Transfer Protocol}
\newacronym{ftps}{FTPS}{File Transfer Protocol Secure}
\newacronym{gps}{GPS}{Global Positioning System}
\newacronym{gprs}{GPRS}{General Packet Radio Service}
\newacronym{gsm}{GSM}{Global System for Mobile communications}
\newacronym{ieee}{IEEE}{Institute of Electrical and Electronics Engineers}
\newacronym{igrp}{IGRP}{Interior Gateway Routing Protocol}
\newacronym{imap}{IMAP}{Internet Message Access Protocol}
\newacronym{ip}{IP}{Internet Protocol}
\newacronym{ipv4}{IPV4}{Internet Protocol v4}
\newacronym{ipv6}{IPV6}{Internet Protocol v6}
\newacronym{ipv4}{IPv4}{Internet Protocol v4}
\newacronym{ipv6}{IPv6}{Internet Protocol v6}
\newacronym{irc}{IRC}{Internet Relay Chat}
\newacronym{isis}{ISIS}{Intermediate System to Intermediate System}
\newacronym{isis}{IS-IS}{Intermediate System to Intermediate System}
\newacronym{isp}{ISP}{Internet Service Provider}
\newacronym{l2}{L2}{Layer 2}
\newacronym{l2vpn}{L2VPN}{Layer 2 Virtual Private Network}
@ -43,15 +46,15 @@
\newacronym{lacp}{LACP}{Link Aggregation Protocol}
\newacronym{lan}{LAN}{Local Area Network}
\newacronym{mac}{MAC}{Media Access Control address}
\newacronym{metdst}{METDST}{Middle European Time Daylight Saving Time}
\newacronym{metdst}{MET-DST}{Middle European Time Daylight Saving Time}
\newacronym{mkc}{MKC}{Mikkel Krøll}
\newacronym{mpls}{MPLS}{Multiprotocol Label Switching}
\newacronym{mst}{MST}{Multiple Spanning Tree}
\newacronym{ntp}{NTP}{Network Time Protocol}
\newacronym{osi}{OSI}{Open Systems Interconnection}
\newacronym{ospf}{OSPF}{Open Shortest Path First}
\newacronym{ospfv3}{OSPFV3}{Open Shortest Path First v3}
\newacronym{pagp}{PAGP}{Port Aggregation Protocol}
\newacronym{ospfv3}{OSPFv3}{Open Shortest Path First v3}
\newacronym{pagp}{PAgP}{Port Aggregation Protocol}
\newacronym{pop3}{POP3}{Post Office Protocol}
\newacronym{pvrst}{PVRST}{Per Vlan Rapid Spanning Tree}
\newacronym{pvrst+}{PVRST+}{Per Vlan Rapid Spanning Tree Plus}
@ -68,13 +71,13 @@
\newacronym{snmp}{SNMP}{Simple Network Management Protocol}
\newacronym{sntp}{SNTP}{Secure Network Time Protocol}
\newacronym{sp}{SP}{Service Provider}
\newacronym{src}{SRC}{Source}
\newacronym{src}{src}{source}
\newacronym{ssh}{SSH}{Secure Shell}
\newacronym{stp}{STP}{Spanning Tree Protocol}
\newacronym{tcn}{TCN}{Topology Change Notification}
\newacronym{tcp}{TCP}{Transmission Control Protocol}
\newacronym{tftp}{TFTP}{Trivial File Transfer Protocol}
\newacronym{toc}{TOC}{Table Of Contents}
\newacronym{toc}{ToC}{Table of Contents}
\newacronym{udld}{UDLD}{Unidirectional Link Detection}
\newacronym{udp}{UDP}{User Datagram Protocol}
\newacronym{utc}{UTC}{Coordinated Universal Time}

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@ -16,7 +16,28 @@ service timestamps debug datetime msec localtime show-timezone
service timestamps log datetime msec localtime show-timezone
\end{txt}
\fig{ntp/ntp}{ntp}{\gls{ntp}}
\gls{ntp} servers are a hierarchical tree with stratum 0 servers as the authoritative in the tree. These servers get their time from either \gls{gprs} satellites or atomic clocks {\footnotesize (i.e. an authoritative time \gls{src})}.
\subsection{Characteristics}
\begin{itemize}
\item Uses \gls{udp} port 123 on both \gls{src} and \gls{dst},
\item polling interval ranging from 64-1024 sec. Length of interval is dependant upon network cond.,
\item large differences between \gls{ntp} reference time and local client time will result in increased pooling interval.
\end{itemize}
\fig{ntp/ntpstratum}{ntpstratum}{Stratum levels}
\section{The old NTP from \tsq{85}}
\section{Secure NTP}
\subsection{Characteristics}
\begin{itemize}
\item
\end{itemize}

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