From: Roland Hieber Date: Sun, 8 Dec 2013 02:26:49 +0000 (+0100) Subject: finish addressing X-Git-Tag: erste-version~12 X-Git-Url: https://git.rohieb.name/skm-ma-ws1314.git/commitdiff_plain/3c87e67ce62440f6132d63d3adb69a4df71cfa6f?ds=sidebyside finish addressing --- diff --git a/address-allocation.tex b/address-allocation.tex index 8970d2d..4198074 100644 --- a/address-allocation.tex +++ b/address-allocation.tex @@ -35,31 +35,30 @@ to. There are several ways of achieving this: \end{itemize} -\todo - \paragraph{IPv4 Link-Local Addressing} -Link-Local Addressing uses the IPv4 subnet 169.254.0.0/16 for addressing. Every -device first chooses a random address from that address space. Then it checks if -the chosen address is used by any other device on the network by probing the -chosen address, which is usually done using the ARP protocol. If the probing -process results that the address is not used on the network (e.~g. no device -returned an ARP response during a random time interval), the device claims its -chosen address and uses it for communication on the IPv4 layer. If the chosen -address is already used, the device continues the process, subsequently choosing -a new random address and trying to claim it, until a free address has been -found. +\term{Link-Local Addressing}, also known as \term{Automatic Private IP +Addressing (APIPA)} or \term{Zeroconf}, uses the IPv4 subnet +\code{169.254.0.0/16} for addressing. Every device first chooses a random +address from that address space. Then it checks if the chosen address is used +by any other device on the network by probing the chosen address, which is +usually done using the ARP protocol. If the probing process results that the +address is not used on the network (e.~g. no device returned an ARP response +during a random time interval), the device claims its chosen address and uses it +for communication on the IPv4 layer. If the chosen address is already used, the + device continues the process, subsequently choosing a new random address and + trying to claim it, until a free address has been found. \paragraph{IPv6 Stateless Address Autoconfiguration} -Similar to IPv4 Link-Local Addressing, devices configured with IPv6 Stateless -Addressing Autoconfiguration use an IPv6 address from the subnet fe80::/64. -Then, an \emph{interface identifier} is generated using the interface's MAC -address. Since MAC addresses must be unique in the network, a unique IPv6 -address is obtained by combining the subnet prefix and the interface identifier. -To ensure that no other device exists with this generated IPv6 address, the -device performs \emph{Duplicate Address Detection} on the network through -\emph{Neighbor Advertisement} messages and listening for \emph{Neighbor +Similar to IPv4 Link-Local Addressing, devices configured with \term{IPv6 +Stateless Addressing Autoconfiguration} use an IPv6 address from the subnet +\code{fe80::/64}. First, an \term{interface identifier} is generated using the +interface's MAC address. Since MAC addresses must be unique in the network, a +unique IPv6 address is obtained by combining the subnet prefix and the interface +identifier. To ensure that no other device exists with this generated IPv6 +address, the device performs \term{Duplicate Address Detection} on the network +through \term{Neighbor Advertisement} messages and listening for \term{Neighbor Solicitation} messages. If such messages are received from other hosts, the configured address cannot be used by the device and must be discarded. Therefore, in order to use IPv6 effectively, it must be guarranteed that MAC @@ -67,15 +66,8 @@ addresses are unique on the network. In contrast to IPv4 Link-Local Addressing, IPv6 Stateless Address Autoconfiguration can also be used with a central server. In this case, a -central server broadcasts \emph{Router Advertisement} messages on the network which -contain a global network prefix. The hosts on the network can then use that -prefix instead to configure a global IPv6 address. - -addressing - -automatic address configuration via Zeroconf/APIPA (IPv4, \cite{rfc3927}) or -IPv6 stateless auto-configuration \cite{rfc4862} - -\pages{1} +central server broadcasts \term{Router Solicitation} messages on the network +which contain a global network prefix. The hosts on the network can then use +that prefix instead to configure a global IPv6 address. % vim: set ft=tex et ts=2 sw=2 : diff --git a/main.tex b/main.tex index 3d26e5e..7044ce7 100644 --- a/main.tex +++ b/main.tex @@ -6,6 +6,8 @@ \newcommand{\pages}[1]{\marginpar{#1 pages}} \newcommand{\todo}{\textcolor{red}{TODO} \\} +\newcommand{\term}[1]{\emph{#1}} +\newcommand{\code}[1]{\texttt{#1}} \title{Chatty Things -- Making the Internet of Things Readily Usable for the Masses with XMPP}