\term{Multicast DNS}~\cite{rfc6762} (mDNS) describes an extension to the Domain
Name System that allows DNS resource records to be distributed on multiple hosts
in a network, therefore avoiding central authorities and enabling every host to
-publish its own entries.
+publish its own entries. For that purpose, a special domain, usually
+named \code{.local}, is used.
-Software that supports resolution of mDNS records listens on the reserved
+Software that supports mDNS listens on the reserved
link-local multicast address \code{224.0.0.251} (for IPv4 queries) or
\code{FF02::FB} (for IPv6 queries) on UDP port 5353 for incoming queries.
Queries sent to those multicast address and port are standard DNS queries.
This is a two-step process, consisting of \term{Service Instance Enumeration}
and \term{Service Instance Resolution}.
-\begin{figure}[htop]
+\begin{figure}[top]
\centering
\includegraphics[width=0.9\textwidth]{dnssd-mock.jpg}
\caption{DNS-SD: Service Instance Enumeration and Resolution