108 lines
4.7 KiB
TeX
108 lines
4.7 KiB
TeX
%** Introduction.tex: Contains an introduction to
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% the topic and motivates the work.
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% State what the reader can find where.
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%** Problem.tex: Documentation in own words of the problem to
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% be addressed in this document:
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% What is the challenge, why is it useful what you
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% plan to do.
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%% In \ref{introduction} we start with our introduction to the problem that we
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%% are going to address. Since we do not want to waste the readers time we
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%% go and show the essential issues of latex in section
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%% \ref{chapter2:essentials}.
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\chapter{\label{introduction}Introduction}
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In this chapter we give an introduction about the topic of the master
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thesis, the motivation, and problems that we address. We explain the
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current state of IPv4 exhaustion and IPv6 adoption and describe how
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it motivates our work to support to ease transition to IPv6 networks.
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% ----------------------------------------------------------------------
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\section{\label{introduction:ipv4ipv6}IPv4 Exhaustion and IPv6 Adoption}
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The Internet has almost completely run out of public IPv4 space. The
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5 Regional Internet Registries (RIRs) report IPv4 exhaustion worldwide
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\cite{ripe_exhaustion},
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\cite{apnic_exhaustion},
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\cite{lacnic:_ipv4_deplet_phases},
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\cite{afrinic:_afrin_ipv4_exhaus},
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\cite{arin:_ipv4_addres_option}.
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Figure \ref{fig:riripv4rundown} contains summarised data from all RIRs
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and projects complete IPv4 addresses depletion by 2021.
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The LACNIC project even predicts complete exhaustion for 2020 as shown
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in figure \ref{fig:lacnicexhaust}.
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\begin{figure}[h]
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\includegraphics[scale=0.5]{rir-ipv4-rundown}
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\centering
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\caption{RIR IPv4 rundown projection~\cite{huston:_ipv4_addres_repor}}
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\label{fig:riripv4rundown}
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\end{figure}
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\begin{figure}[h]
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\includegraphics[scale=0.7]{lacnicdepletion}
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\centering
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\caption{LACNIC Exhaustion projection~\cite{lacnic:_ipv4_deplet_phases}}
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\label{fig:lacnicexhaust}
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\end{figure}
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On the other hand, IPv6 adoption grows significantly, with at least
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three countries (India, US, Belgium) surpassing 50\%
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adoption~\cite{akamai:_ipv6_adopt_visual},
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\cite{vyncke:_ipv6_deploy_aggreg_status},
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\cite{cisco:_ipv6}. Traffic from Google users reaches almost 30\% as
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of 2019-08-08~\cite{google:_ipv6_googl}, see figure \ref{fig:googlev6}.
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We conclude that IPv6 is a technology strongly gaining importance.
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IPv4 depletion is estimated to be happening worldwide in the
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next years. Thus more devices will be using IPv6, while communication
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with legacy IPv4 devices still needs to be provided.
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% ok
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% ----------------------------------------------------------------------
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\section{\label{introduction:motivation}Motivation}
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\begin{figure}[h]
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\includegraphics[scale=0.2]{googlev6}
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\centering
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\caption{Google IPv6 Statistics from~\cite{google:_ipv6_googl}}
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\label{fig:googlev6}
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\end{figure}
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IPv6 hosts and IPv4 hosts cannot directly connect to each other,
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because the protocols are incompatible to each other.
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To allow communication between different protocol hosts,
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several transition mechanisms have been
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proposed~\cite{wikipedia:_ipv6},~\cite{rfc4213}.
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\begin{figure}[h]
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\includegraphics[scale=0.4]{v6-v6-separated}
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\centering
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\caption{Separated IPv6 and IPv4 network segments}
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\label{fig:v6v4separated}
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\end{figure}
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However installation and configuration of the transition mechanism
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usually require in-depth knowledge about both protocols and require
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additional hardware to be added in the network.
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In this thesis we show an in-network transition method based on
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NAT64~\cite{rfc6146}. Compared to traditional NAT64 methods which
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require hosts to explicitly use an extra device in the
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network,\footnote{Usually the default router will take this role.}
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our proposed method is transparent to the hosts.
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This way the routing and network configuration does not need to be
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changed to support NAT64 within a network.
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Currently network operators have to focus on two network stacks when
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designing networks: IPv6 and IPv4. While in a small scale setup this
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might not introduce significant complexity, figure
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\ref{fig:v6v4separated} shows how the complexity quickly grows
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even with a small number of hosts.
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The proposed in-network solution does not only ease the installation and
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deployment of IPv6, but it also allows line speed translation, because
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it is compiled into target dependent low level code that can run in
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ASICs~\cite{networks:_tofin},
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FPGAs~\cite{netfpga:_p4_netpf_public_github}
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or even in
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software~\cite{_implem_your_switc_target_with_bmv2}. Figure
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\ref{fig:v6v4mixed} shows how the design differs for an in-network
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solution.
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Even on fast CPUs, software solutions like
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tayga~\cite{lutchansky:_tayga_simpl_nat64_linux}
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can be CPU bound (see section \ref{results:softwarenat64}) and are
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incapable of translating protocols at line speed.
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