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WIP: Updated section bout spanning tree.

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chhan11 2017-05-23 12:55:02 +02:00
parent 67a45712c1
commit d615c2bc3f
2 changed files with 74 additions and 12 deletions

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@ -1,8 +1,4 @@
\chapter{Protocols} \chapter{Protocols Layer 2}
\subimport{./section/}{routednetwork}
\newpage
\subimport{./section/}{switchednetwork} \subimport{./section/}{switchednetwork}

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@ -34,24 +34,90 @@ When a switch is enabled for Spanning Tree. One of the following roles will have
\subsection{Standards} \subsection{Standards}
\subsubsection{STP} \begin{itemize}
\item STP {\scriptsize Spanning Tree Protocol}
\subsubsection{PVST} \begin{itemize}
\item Ieee 802.1D
\subsubsection{RPVST+} \item Was created in a time where bridged networks was the norm.
\item Supports a single vlan/lan.
\subsubsection{MST} \end{itemize}
\item CST {\scriptsize Common Spanning Tree}
\begin{itemize}
\item An evolution of stp
\item Cst still only supports one stp instance.
\item But cst do thou in contrast to stp support \textit{multiple} vlans.
\end{itemize}
\item PVST {\scriptsize Per Vlan Spanning Tree}
\begin{itemize}
\item Now obsolute and succeded by pvst+
\end{itemize}
\item PVST+ {\scriptsize Per Vlan Spanning Tree Plus}
\begin{itemize}
\item Runs an instance of stp per vlan.
\item Can guarante better utilization of available network bandwidth.
\item Root bridge and port priorities can be configured per vlan.
\end{itemize}
\item RSTP {\scriptsize Rapid Spanning Tree Protocol}
\begin{itemize}
\item Ieee 802.1w
\item A future development of the original 802.1D standard meant to provide faster convergance. As the original stp standard wasn't actually that fast.
\end{itemize}
\item RPVST+ {\scriptsize Rapid Per Vlan Spanning Tree Plus}
\begin{itemize}
\item A cisco implementation of rstp based upon pvst+.
\end{itemize}
\item MST {\scriptsize Multiple Spanning Tree}
\begin{itemize}
\item Originally a cisco developed protocol. Mst has since been developed as an ieee standard.
\item Mst can as cst map multiple vlans to a single stp instance.
\item Mst \textit{differently} than cst supports multiple stp instances.
\item Fx. Instance 1: Vlan 1-99, Instane 2: Vlan 100-199.
\end{itemize}
\end{itemize}
\subsection{Features} \subsection{Features}
\subsubsection{BPDU}
\textbf{B}ridge \textbf{P}rotocol \textbf{D}ata \textbf{U}nits is on cisco equipment sent out every 2 seconds and generally catogorizes into 2 categories:
\begin{itemize}
\item \textit{Configuration} bpdu used for stp calculations and
\item \textit{Topology change notifications} bpdus used to notify other network nodes of a change in the network.
\end{itemize}
Any network node with switchports and stp + bpdu enabled sends out bpdu packets with the ports mac as the src address. The destination mac is is designated stp multicast addr 01:80:C2:00:00:00.
\subsubsection{Root bridge}
Using a \textbf{R}oot \textbf{B}rigde as the reference point for the stp instance and calculation of root/designated/non-designated ports.\\This election process uses a pre-configured bridge priority (ranges from $0$ to $2^{16}$) (defaults to $2^{15}$). If a tie in priority is found the switch in possession of the lowest mac address wins the root bridge election.
\subsubsection{Port}
\begin{itemize} \begin{itemize}
\item PortFart \item PortFart
\begin{itemize}
\item
\end{itemize}
\item UplinkFast \item UplinkFast
\begin{itemize}
\item
\end{itemize}
\item BackboneFast \item BackboneFast
\begin{itemize}
\item
\end{itemize}
\end{itemize}
\subsubsection{Loop prevention}
\begin{itemize}
\item BPDU Guard \item BPDU Guard
\item BPDU Filter \item BPDU Filter
\item Root Guard \item Root Guard
\item Loop Guard \item Loop Guard
\end{itemize}
\subsubsection{Link}
\begin{itemize}
\item Unidirectional Link Detection (UDLD) \item Unidirectional Link Detection (UDLD)
\item FlexLinks \item FlexLinks
\end{itemize} \end{itemize}