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WIP: Updated bgp
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@ -156,6 +156,7 @@
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\newacronym{tlv}{TLV}{Type, Length, Value}
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\newacronym{toc}{ToC}{Table of Contents}
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\newacronym{tosdr}{ToS;DR}{Terms of Service; Didn't Read}
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\newacronym{ttl}{TTL}{Time-to-live}
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\newacronym{udld}{UDLD}{Unidirectional Link Detection}
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\newacronym{udp}{UDP}{User Datagram Protocol}
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\newacronym{utc}{UTC}{Coordinated Universal Time}
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@ -7,14 +7,15 @@
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\section{EIGRP}
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\section{RIP}
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\section{Static}
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\newpage
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\section{BGP}
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\wikicommons{BGP_FSM}
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The protocol of the internet used since 1994.\cite{wiki:Border_Gateway_Protocol}
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Currently based upon \rfc{4271} with updates following in \rcf{6286} \rfc{6608}, \rfc{6793}, \rfc{7606}, \rfc{7607}, \rfc{7705}.
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Currently based upon \rfc{4271} with updates following in \rfc{6286} \rfc{6608}, \rfc{6793}, \rfc{7606}, \rfc{7607}, \rfc{7705}.
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\begin{itemize}
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\item \itemhead{Properties}
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@ -27,20 +28,19 @@ Currently based upon \rfc{4271} with updates following in \rcf{6286} \rfc{6608},
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\begin{itemize}
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\item \itemhead{Route-maps mechanism}
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\begin{itemize}
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\item Routes can be aggregated between \Glspl{as}.
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\item Routes can be aggregated between \glspl{as}.
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\item Properties can be changed on the fly by mathing
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\begin{enumerate*}[label={\alph*)}]
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\item \Gls{bgp} communities,
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\item \Gls{ip} prefix,
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\item \Gls{bgp} as-path,
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\end{enumerate*}
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\begin{mylist}
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\item \gls{bgp} communities,
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\item \gls{ip} prefix,
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\item \gls{bgp} as-path,
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\end{mylist}
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\end{itemize}
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\item
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\end{itemize}
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\item \itemhead{States}
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\begin{enumerate}
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\item Idle: \Gls{bgp} while initializing refuses all incoming connections. Will initiate \Gls{tcp} connection to peer.
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\item Connect: Waits for \Gls{tcp} connection. If \Gls{tcp} is established goes to state OpenSent. If \Gls{tcp} is \textit{un}successful ConnectRetry timer is started and then goes to Active state.
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\item Idle: \gls{bgp} while initializing refuses all incoming connections. Will initiate \gls{tcp} connection to peer.
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\item Connect: Waits for \gls{tcp} connection. If \gls{tcp} is established goes to state OpenSent. If \gls{tcp} is \textit{un}successful ConnectRetry timer is started and then goes to Active state.
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\item Active: When ConnectRetry counter reaches 0 goes to state Connect.
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\item OpenSent: Sends \gls{msg} to remote node. Waits for reply \gls{msg} before going to OpenConfirm.
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\item OpenConfirm: Nodes exchange keepalive \glspl{msg} and goes to Established state if successful.
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@ -48,4 +48,21 @@ Currently based upon \rfc{4271} with updates following in \rcf{6286} \rfc{6608},
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\end{enumerate}
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\end{itemize}
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\subsection[iBGP]{Internal Border Gateway Protocol}
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\gls{ibgp} is running \gls{bgp} within the same \gls{as} between routers. Much like running a general \gls{igrp} in the network.
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Tradition one has to be fearful of creating \textit{routing loops} in the network. \glspl{bgp} mechanism for this is using either \begin{mylist} \item Full Mesh, or \item \glspl{rr} \end{mylist}.
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Problems by running \textit{Full Mesh} is the formula of \[ iBGPsessions = n*(n-1)/2 \] \note{where $ n $ is the number \gls{ibgp} speakers} which results in scaling problems as \gls{ibgp} speakers are added to the \gls{as}.
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\textit{\glspl{rr}} solves this problem by peering with all \gls{ibgp} speakers in the \gls{as}. All \gls{ibgp} speakers are then clients of the \glspl{rr}. This in turn helps maintainability by also advertising routes learnt from \gls{ibgp} clients to clients. Classic filtering/mathing route-maps/prefix-filters can be used to \textit{not} advertise all routes select group of clients from the \glspl{rr}.
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\subsection[eBGP]{External Border Gateway Protocol}
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\gls{ebgp} connections is inherently different from \gls{ibgp} connections. Some assumptions are made such as
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\begin{enumerate}
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\item a \gls{ttl} of 1 is the default\footnote{Multi-hop \gls{ebgp} can thou be configured},
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\item distance is set to 20 compared to 200 for \gls{ibgp} routes,
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\item Next hop does \textit{not} change for \gls{ebgp} routes advertised to \gls{ibgp} neighbours.
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\end{enumerate}
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@ -129,3 +129,8 @@ License: \texttt{\href{https://creativecommons.org/licenses/by-sa/3.0/}{CC BY-SA
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% Usage:
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\newcommand{\rfc}[1]{RFC #1\footnote{\href{https://tools.ietf.org/html/rfc#1}{tools.ietf.org/html/rfc#1}}}
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% Usage: \note{<text>} or \nb{<text>}
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\newcommand{\note}[1]{{\color{Mahogany!20!black}{\small(#1)}}}
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\newcommand{\nb}[1]{\note{#1}}
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@ -2,7 +2,7 @@
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author = "Hector Camba Lainez",
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title = "Cap4 implementing vtp",
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year = "2010",
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url = {https://www.slideshare.net/lucky0679/cap4-implementing-vtp},
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url = {\url{https://www.slideshare.net/lucky0679/cap4-implementing-vtp}},
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note = "[Online; accessed 22-May-2017]"
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}
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@ -13,3 +13,12 @@
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howpublished = {\url{https://orhanergun.net/2017/01/tier-1-tier-2-tier-3-service-providers/}},
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note = "[Online; accessed 17-June-2017]"
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}
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@misc{ Differen15:online,
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author = {\url{http://www.differencebetween.com/author/root/}{Andrew}},
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title = "Difference Between EBGP and IBGP",
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howpublished = {\url{http://www.differencebetween.com/difference-between-ebgp-and-vs-ibgp/}},
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month = "September",
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year = "2011",
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note = "[Online; accessed on 24-June-2017]"
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}
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