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Updated structure.tex and chapter/section/spanningtree.tex

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chhan11 2017-05-26 14:16:09 +02:00
parent 855db4d907
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2 changed files with 25 additions and 4 deletions
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28
chapter/section/spanningtree.tex
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@ -175,8 +175,8 @@ Cisco did on their part early on enhance the original spanning tree standard wit
\item Port does no forwan TCN\footnote{\textbf{Needs finding out what TCN is.}} BPDUs either.
\item PortFast can be enabled either A) per port \textit{or} B) globally for all ports in access mode.
\begin{enumerate}
\item Per port: \footnote{Accesss port}\\\cliline{switch(config-if)# spanning-tree portfast}
\item Per port: \footnote{Trunk port}\\\cliline{switch(config-if)# spanning-tree portfast trunk}
\item Per port: {\footnotesize Accesss port}\\\cliline{switch(config-if)# spanning-tree portfast}
\item Per port: {\footnotesize Trunk port}\\\cliline{switch(config-if)# spanning-tree portfast trunk}
\item Globally:\\\cliline{switch(config)# spanning-tree portfast default}
\end{enumerate}
\end{itemize}
@ -204,7 +204,7 @@ Cisco did on their part early on enhance the original spanning tree standard wit
\begin{enumerate}
\item Switch will search for alternative path to root.
\item If BPDU recieved on blocked port. Port considered alternative path path to root.
\item If alternate path identified. RQL\footnote{\textbf{R}equest \textbf{L}ink \textbf{B}locking} packets are out for identify either A) an alternative path to the root bridge \textit{or} B) an up-/downstream switch with a path to the root bridge.
\item If alternate path identified. RQL{\footnotesize \textbf{R}equest \textbf{L}ink \textbf{B}locking} packets are out for identify either A) an alternative path to the root bridge \textit{or} B) an up-/downstream switch with a path to the root bridge.
\end{enumerate}
\end{itemize}
\end{itemize}
@ -240,18 +240,38 @@ Cisco did on their part early on enhance the original spanning tree standard wit
\end{itemize}
\item Root Guard
\begin{itemize}
\item Prevents external switches from becoming roots
\item \st{Prevents external switches from becoming roots}
\item If enabled, prevents any ports from becoming a root-port. Ports will remain as designated ports \textit{effectivily} preventing the switch becoming the root bridge.
\item This, too, behaves in s similiar manner as BPDU guard, putting the port in \texttt{err-disable} mode when a BPDU packet is recieved on the port.
\item Enabled per-port with\\\cliline{switch(config-if)# spanning-tree guard root}
\end{itemize}
\item Loop Guard
\begin{itemize}
\item Prevents an alternate port from becoming the designated port if no BPDUs are received
\begin{enumerate}
\item Normally when cisco swicthes stop recieving BPDUs ingress in a port. The port will go to listeting, learning, forwarding state equaling a loop.
\item With Loop guard enabled the will go to \texttt{loop-inconsistent} blocking state instead.
\end{enumerate}
\item Enabled per-port\\\cliline{switch(config-if)# spanning-tree guard loop}
\item Enabled globally\\\cliline{switch(config)# spanning-tree loopguard default} {\small only on p2p links}
\item Works on per-vlan basis when PVSTP is used.
\end{itemize}
\item \textbf{Beware} root and loop guard is mutually exclusive
\begin{itemize}
\item Root guard works on designated ports and does not allow the ports to become \textit{non}-designated ports, where
\item Loop guard works on \textit{non}-designated ports and does not allow the ports to become designated ports {\footnotesize though expiration of times}.
\end{itemize}
\subsection{Link}
\begin{itemize}
\item Unidirectional Link Detection (UDLD)
\begin{itemize}
\item Cisco proprietary feature.
\item By default only enables on fiber optic links.
\item Works by sending packes every 15 seconds (default timer). If not packet is recieved back, the port can either log (default) a messaage or actively try to re-establish the link (aggresive). 1 packet/second for 8 sec. is send. If non is returned the port will go to \texttt{err-disable} state.
\item \cliline{switch(config)# udld \{enable | aggresive\}}
\item
\item FlexLinks
\end{itemize}

1
structure.tex
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@ -25,6 +25,7 @@
%\usepackage{lipsum}
%\usepackage{titling}
\usepackage{transparent}
\usepackage{soul}
\bibliographystyle{unsrtnat} %styles list https://www.sharelatex.com/learn/Natbib_bibliography_styles