diff --git a/7 Multicast and realtime service/Multicast and realtime service.tex b/7 Multicast and realtime service/Multicast and realtime service.tex index 15ccb20..0e788e5 100644 --- a/7 Multicast and realtime service/Multicast and realtime service.tex +++ b/7 Multicast and realtime service/Multicast and realtime service.tex @@ -76,14 +76,14 @@ \section{Linux Multicast Routing Table} Save the new routing table. \begin{report} - \item Submit the routing table you saved. + \item Submit the routing table you saved. \end{report} \section{Multicast Membership} Execute \lstinline{netstat -g} to show the multicast group memberships for all the interfaces in your host (for example \textit{h1}). \begin{report} - \item How many multicast groups did the interface belong to? What were the groups? Explain the meaning of the group IDs. + \item How many multicast groups did the interface belong to? What were the groups? Explain the meaning of the group IDs. \end{report} \section{Multicast \texttt{ping}} @@ -100,11 +100,11 @@ \section{Multicast \texttt{ping}} \end{lstlisting} \begin{report} - \item Which hosts replied when the multicast address was pinged? - Which hosts replied when the broadcast address was pinged? - Verify you answers with hosts config \path{/proc/sys/net/ipv4/icmp_echo_ignore_broadcasts}. + \item Which hosts replied when the multicast address was pinged? + Which hosts replied when the broadcast address was pinged? + Verify you answers with hosts config \path{/proc/sys/net/ipv4/icmp_echo_ignore_broadcasts}. - \item In each case, was there a reply from \textit{h0} and \textit{h1}? + \item In each case, was there a reply from \textit{h0} and \textit{h1}? \end{report} \section{Multicast vs Unicast} @@ -122,11 +122,11 @@ \section{Multicast vs Unicast} Save the frames captured for the lab report. \begin{report} - \item Compare the source and destination MAC addresses of the frames you captured. + \item Compare the source and destination MAC addresses of the frames you captured. - \item Use one of the multicast frames captured to explain how a multicast group address is mapped to a multicast MAC address. - For the two multicast frames captured, do they have the same destination MAC address? - Why? + \item Use one of the multicast frames captured to explain how a multicast group address is mapped to a multicast MAC address. + For the two multicast frames captured, do they have the same destination MAC address? + Why? \end{report} \section{Simple UDP Multicast Client and Server} @@ -148,12 +148,12 @@ \section{Simple UDP Multicast Client and Server} Save the captured multicast datagram sent by \lstinline{netspyd} and exit the \lstinline{telnet} (or \lstinline{ssh}) session. \begin{report} - \item From the \lstinline{tcpdump} output, how many messages are sent by \lstinline{netspyd} when a new user logged in to \textit{h0}? - From the \lstinline{netspy} outputs on all the hosts, how many copies of the message are received in total? + \item From the \lstinline{tcpdump} output, how many messages are sent by \lstinline{netspyd} when a new user logged in to \textit{h0}? + From the \lstinline{netspy} outputs on all the hosts, how many copies of the message are received in total? - \item Did \textit{h0}, where the multicast sender, \lstinline{netspyd}, was running, receive the multicast datagram? - Why? - If yes, through which interface did \textit{h0} receive this datagram? + \item Did \textit{h0}, where the multicast sender, \lstinline{netspyd}, was running, receive the multicast datagram? + Why? + If yes, through which interface did \textit{h0} receive this datagram? \end{report} \section{\texttt{ping} Replay} @@ -255,9 +255,9 @@ \section{Multicast Message} Now, login to \textit{h1} from \textit{h2} in your group, then logout. \begin{report} - \item Can you ping a host on the other side of the router? - Will the router forward a multicast IP datagram to the other side? - Justify your answers. + \item Can you ping a host on the other side of the router? + Will the router forward a multicast IP datagram to the other side? + Justify your answers. \end{report} \section{IGMP Types} @@ -272,10 +272,10 @@ \section{IGMP Types} Terminate the \lstinline{tcpdump} programs and analyze the IGMP leave message you captured. \begin{report} - \item What is the value of the Time-to-Live (TTL) field for the IGMP messages? - Why do we not set the TTL to a larger number? + \item What is the value of the Time-to-Live (TTL) field for the IGMP messages? + Why do we not set the TTL to a larger number? - \item What is the default frequency at which the router sends IGMP queries? + \item What is the default frequency at which the router sends IGMP queries? \end{report} \section{Router Join to Multicast-Group} @@ -286,7 +286,7 @@ \section{Router Join to Multicast-Group} \end{lstlisting} \begin{report} - \item Explain why the above command fails. + \item Explain why the above command fails. \end{report} \part{Multicast Routing Exercises}\label{sec:multicast-routing} @@ -368,10 +368,11 @@ \section{Multicast Multi-Hub} % Note that most of the router interfaces use their default IP addresses, only the \textit{ethernet0} interface of Router4 needs to be changed to 128.238.63.4. Enable linux multicast routing in all the hosts (see \autoref{sec:linux-multicast-routing}). - Enable PIM multicast routing in all the routers (see \autoref{sec:config-router}). + All routers pre-configured in \textit{GN3} \hyperref[fig:7.14]{Figure~7.14} - Run \lstinline{tcpdump ip multicast} or \lstinline{wireshark} on all the hosts. + Run \lstinline{tcpdump ip multicast} or \lstinline{wireshark} on all subnet (at least one host). + Maybe you need to restart (or reload) routers to capture all packet from start state. Execute \lstinline{./netspy 224.111.111.111 1500} on \textit{h0}, \textit{h2}, \textit{h3}, \textit{h5}, and \textit{h6}. @@ -383,6 +384,7 @@ \section{Multicast Multi-Hub} Can you see the \lstinline{netspy} messages on the 128.238.65.0 (or the 128.238.61.0) subnet in the \lstinline{tcpdump} output? Terminate the \lstinline{netspy} program on \textit{h6} (or \textit{h0}). + Can you see the \lstinline{netspy} messages on the 128.238.65.0 (or the 128.238.61.0) subnet? \footnote{If IGMPv1 is used, a participant does not send a leave message when it leaves the group. In this case, the membership record in the router expires in 120 seconds. @@ -393,7 +395,7 @@ \section{Multicast Multi-Hub} What is the destination IP address used in this PIM routing packet? \begin{report} - \item Answer the above questions. + \item Answer the above questions. \end{report} \section{Multicast Tree} @@ -401,7 +403,11 @@ \section{Multicast Tree} The \lstinline[language={cisco}]{mstat} command is executable in the \textit{Privileged EXEC} mode. You can always type \lstinline[language={cisco}]{?} to get help on the syntax of the command. - Generate multicast packet when execute command for specific source. + Generate multicast packet when execute command for \textit{h4}. + + \begin{report} + \item Report the \lstinline[language={cisco}]{mstat} output for \textit{h4} on \textit{R1}. + \end{report} \section{Multicast TTL} Keep \lstinline{netspy} running on all the hosts. @@ -427,9 +433,9 @@ \section{Multicast TTL} Answer the same question. \begin{report} - \item Answer the above questions. - - \item What is the use of the TTL threshold in the router interface? + \item Answer the above questions. + + \item What is the use of the TTL threshold in the router interface? \end{report} \part{Multicast Video Streaming Exercise}