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%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{amblas5687}
\pdfinfo{
  /Title (networking-final.pdf)
  /Creator (Cheatography)
  /Author (amblas5687)
  /Subject (Networking Final Cheat Sheet)
}

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\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
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\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Networking Final Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{amblas5687} via \textcolor{DarkBackground}{\uline{cheatography.com/36771/cs/11562/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}amblas5687 \\
  \uline{cheatography.com/amblas5687} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 24th April, 2017.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

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% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{4}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{4.4 Subnets}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Communication internal, able without router.} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Amount of IP bits must match, indicated by /x on address, x is amount of bits for matching in subnet, rest used for host.} \tn 
% Row Count 4 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Sometimes can be represented using an IP address, in binary all bits that are 1 are the amount for subnet.} \tn 
% Row Count 7 (+ 3)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{4.4 NAT}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{In routers, has public and private addresses, wraps private address in public NAT.} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Private addresses either 10.0.0 or 192.168.1.} \tn 
% Row Count 3 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{NAT makes forwarding table, associates internal IP and port with NAT IP and new chosen NAT port.} \tn 
% Row Count 5 (+ 2)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Each socket will have its own entry.} \tn 
% Row Count 6 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{4.4 Adressing}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Addressing is dotted decimal, a.b.c.d, each decimal separating a byte.} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Roughly 2\textasciicircum{}32 addresses with IPv4.} \tn 
% Row Count 3 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{DHCP, Interfaces, ICMP}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{DHCP is client/server setup, assigns IP from pool, releases once host is done.} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Interfaces: a connection with a host/router and link, associated with IP addresses.} \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{ICMP, protocol, error communication, above IP} \tn 
% Row Count 5 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{Forwarding Table}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Tells you what link to send to based on destination IP.} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Splits the destination IPs into ranges in the forwarding table.} \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Choose range with longest match.} \tn 
% Row Count 5 (+ 1)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{To make, split destination IP ranges by looking at where bits deviate.} \tn 
% Row Count 7 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{x{0.85825 cm} x{2.57475 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{4.5 Types of Routing Algorithms}}  \tn
% Row 0
\SetRowColor{LightBackground}
Global & All routers have the knowledge of the network system. Link state algorithms. Dijkstra's algorithm. \tn 
% Row Count 4 (+ 4)
% Row 1
\SetRowColor{white}
\seqsplit{Decentralized} & Routers only know information about neighbors. Learns network through neighbors. Distance vector algorithms. \tn 
% Row Count 8 (+ 4)
% Row 2
\SetRowColor{LightBackground}
Static & Changes slowly over time. \tn 
% Row Count 9 (+ 1)
% Row 3
\SetRowColor{white}
Dynamic & Changes more quickly. \tn 
% Row Count 10 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{4.1-4.3}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{What does network layer do? Transports segments, wraps segments in datagram, in every host, uses IP.} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{How do routers work? Use routing algorithm to create forwarding table. Move datagrams from input to output, use switching fabric. Works on layer 3.} \tn 
% Row Count 5 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Key network functions: Routing: Determine the route to dest. Forwarding: Deciding the correct output port to send a packet on. Forwarding tables tell router where to send datagram.} \tn 
% Row Count 9 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{Hierarchical Routing}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Divide network into small groups. A router is chosen as gateway to outside networks. All routers in group run same routing algorithm.% Row Count 3 (+ 3)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{x{1.0299 cm} x{2.4031 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{4.4 classful IP and CIDR}}  \tn
% Row 0
\SetRowColor{LightBackground}
Class A: & 8 bits network, 24 bits host. \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
Class B: & 16 bit network, 16 bits host. \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
Class C & 24 bit network, 8 bits host. \tn 
% Row Count 5 (+ 1)
% Row 3
\SetRowColor{white}
Classless (CIDR): & allows any choice of \# bits for network. \tn 
% Row Count 7 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{4.4 Fragmentation}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Break data to fit on link.} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Formula for fragmenting datagram: ceiling (datagram – IP header / MTU – IP header)} \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Formula for fragmenting raw data: ceiling (bytes / MTU – IP header – transport layer header)} \tn 
% Row Count 5 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{4.4 IPv6}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Removed fragmentation. Increased address size to 128 bits. 40 byte fixed header.} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Version: IP version.} \tn 
% Row Count 3 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Traffic class: type of traffic.} \tn 
% Row Count 4 (+ 1)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Payload length: how much data.} \tn 
% Row Count 5 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Next header: upper layer protocol to deliver to.} \tn 
% Row Count 6 (+ 1)
% Row 5
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Hop limit: how many hops allowed.} \tn 
% Row Count 7 (+ 1)
% Row 6
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Source and dest. addresses: 128 bits.} \tn 
% Row Count 8 (+ 1)
% Row 7
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Data: what data is transported.} \tn 
% Row Count 9 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{x{1.13289 cm} x{2.30011 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{4.4 IPv4}}  \tn
% Row 0
\SetRowColor{LightBackground}
Protocol version: & what version running. \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
Header length: & length of header, fixed 20 bytes + optional field. \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
Type of the data: & Different types of datagrams exist. \tn 
% Row Count 6 (+ 2)
% Row 3
\SetRowColor{white}
Datagram length: & data + header \tn 
% Row Count 8 (+ 2)
% Row 4
\SetRowColor{LightBackground}
Identifier: & identify fragments of IP datagram, data from same datagram has same number \tn 
% Row Count 11 (+ 3)
% Row 5
\SetRowColor{white}
Flags: & indicate beginning of fragmentation or if allowed, uses 3 bits. First bit always 0. Second bit is 0 or 1, 0 means fragment, 1 means can't. Last bit 0 or 1, 0 means no more fragments, 1 means more. \tn 
% Row Count 19 (+ 8)
% Row 6
\SetRowColor{LightBackground}
Offset: & used to rebuild fragment. \tn 
% Row Count 20 (+ 1)
% Row 7
\SetRowColor{white}
Time to live: & How many hops before dropped, resets at router, drop at 0. \tn 
% Row Count 23 (+ 3)
% Row 8
\SetRowColor{LightBackground}
Upper layer: & upper layer protocol to pass to. \tn 
% Row Count 25 (+ 2)
% Row 9
\SetRowColor{white}
Header checksum: & check for errors \tn 
% Row Count 27 (+ 2)
% Row 10
\SetRowColor{LightBackground}
Source and dest. IP: & 32 bits. \tn 
% Row Count 29 (+ 2)
% Row 11
\SetRowColor{white}
Data: & data carried. \tn 
% Row Count 30 (+ 1)
\end{tabularx}
\par\addvspace{1.3em}

\vfill
\columnbreak
\begin{tabularx}{3.833cm}{x{1.13289 cm} x{2.30011 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{4.4 IPv4 (cont)}}  \tn
% Row 12
\SetRowColor{LightBackground}
Options: & allows increase in header. \tn 
% Row Count 1 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{x{1.40753 cm} x{2.02547 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{5.1 Link layer}}  \tn
% Row 0
\SetRowColor{LightBackground}
What is it? & Getting messages from one link to next, one hop communication. \tn 
% Row Count 3 (+ 3)
% Row 1
\SetRowColor{white}
How does info change? & From link to link. \tn 
% Row Count 5 (+ 2)
% Row 2
\SetRowColor{LightBackground}
What are transmission units? & Frames. \tn 
% Row Count 7 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{5.1 Link layer services}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Framing: putting datagrams into frames.} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Link Access: rules for multiple users accessing link.} \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Reliable delivery: uses re-transmissions and ACKs. For direct connection links. Only used on error prone links.} \tn 
% Row Count 6 (+ 3)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{5.3 Types of links}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Point to ponit} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Broadcast: many users share link.} \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Wireless} \tn 
% Row Count 3 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{5.3 MAC protocols}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{MAC protocols allow link sharing.} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Channel partitioning: No collisions, communicate on time intervals.} \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Random access: if collisions, randomly choose time to resend.} \tn 
% Row Count 5 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{5.4 MAC addresses}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{MAC is fixed. IP can change.} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{MAC 48 bits, in hex} \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Host has both MAC and iP.} \tn 
% Row Count 3 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{x{1.09856 cm} x{2.33444 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{Ethernet Frames}}  \tn
% Row 0
\SetRowColor{LightBackground}
Preamble & Wakes up the receiver for transmission. \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
Source and Dest MAC & tell you sender and receiver, 48 bits, hex. \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
Payload & Must be between 46-1500 bytes, data sent. \tn 
% Row Count 6 (+ 2)
% Row 3
\SetRowColor{white}
\mymulticolumn{2}{x{3.833cm}}{Error correction} \tn 
% Row Count 7 (+ 1)
% Row 4
\SetRowColor{LightBackground}
Type & Tells you the upper layer protocol. \tn 
% Row Count 9 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{p{0.3433 cm} x{3.0897 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{Ethernet topology}}  \tn
% Row 0
\SetRowColor{LightBackground}
Bus & hosts connect to same link. \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
Star & hosts connect to switch, switch moves traffic, reduces traffic to router, forwards within subnet, uses MAC address. \tn 
% Row Count 5 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{5.4 ARP}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Maps MAC to IP} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Above link layer, below network layer. ARP packets carried by link layer.} \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Creates tables to map IP and MAC. Entries last approx. 20 mins.} \tn 
% Row Count 5 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{5.4 ARP sending in subnet}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Check ARP table for mapping.} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{If mapping is there, send frame.} \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{If mapping not there, ARP query.} \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Broadcast ARP query for who has an IP.} \tn 
% Row Count 4 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Host with IP responds directly to query host.} \tn 
% Row Count 5 (+ 1)
% Row 5
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Table updated with MAC/IP mapping.} \tn 
% Row Count 6 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{5.4 ARP sending outside subnet}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Can't have destionation's MAC.} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Use MAC for next hop link (router) as destination MAC.} \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Source IP and Dest IP stay same. Source MAC and Dest. MAC change.} \tn 
% Row Count 5 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{3.833cm}}{\bf\textcolor{white}{Switches}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{Operates on layer 2, link layer device, transparent to host (no IP or MAC).} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{3.833cm}}{Self learns by recording interface and MAC of sent frames that cross it. Builds own forwarding table.} \tn 
% Row Count 5 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{3.833cm}}{If no entry in forwarding table, broadcasts frame to all interfaces. Those with the wrong MAC drop it.} \tn 
% Row Count 8 (+ 3)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}