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46 lines
1.5 KiB
TeX
46 lines
1.5 KiB
TeX
\chapter{NTP}
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\gls{ntp} is the source of all evil and \gls{sla}. A network wide source of time configuration for all network nodes, servers, clients etc. is necessary.
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\textbf{Configure timezone}\\In this case it\tsq{s} for \gls{metdst}\textbf{:}
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\begin{txt}
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clock timezone MET 1 0
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clock summer-time MET-DST recurring last Sun Mar 2:00 last Sun Oct 3:00
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\end{txt}
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\textbf{Configure used timezone}\\when doing logging and debugging operations\textbf{:}
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\begin{txt}
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service timestamps debug datetime msec localtime show-timezone
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service timestamps log datetime msec localtime show-timezone
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\end{txt}
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A select number of Cisco switches support synchronization with the hardware clock, too. The standard is to only sync the software clock.\\\cliline{ntp update-calendar}
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\fig{ntp/ntp}{ntp}{\gls{ntp}}
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\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})}.
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\subsection{Characteristics}
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\begin{itemize}
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\item Uses \gls{udp} port 123 on both \gls{src} and \gls{dst},
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\item polling interval ranging from 64-1024 sec. Length of interval is dependant upon network cond.,
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\item large differences between \gls{ntp} reference time and local client time will result in increased pooling interval.
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\end{itemize}
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\fig{ntp/ntpstratum}{ntpstratum}{Stratum levels}
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\section{The old NTP from \tsq{85}}
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\section{Secure NTP}
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\subsection{Characteristics}
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\begin{itemize}
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\item
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\end{itemize}
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