[Autogenerated] Hi, everyone. My name is
Betty do Boys, and welcome to Pluralsight
SSHD Deep Dive Course on DNS DNS is a
crucial part of our everyday life. This
course will cover theory, so we're all on
the same page but also configuration on
the client and server troubleshooting and
securing the protocol. We have an
environment set up in Azure, so we'll get
a chance to capture the packets from
multiple perspectives. We'll be spending
quite a bit of time and wire shark. So
download the latest version from Wire
shark or gig and download the packet
captures from the exercise files tab so
you can follow along. The domain name
system is everywhere yet Why do we need
it, and how does it really work? We're
going to start off with how Dean's works
from a client's perspective, because we
all use drones every time there's a screen
in front of us. Then we'll capture those
packets and wire shark where nothing can
hide. Let's dive in. The internet has
grown to over 370 million domains. That's
just the domains. If we were to calculate
how Maney individual records were
represented by each domain, it would be
incomprehensible. Domain name system
Ordnance is the distributed database that
correlates the words that we is humans
like to use and the numbers that computers
need to use. These are IP addresses for
some of my favorite servers. Now, really?
Quick, tell me what the addresses were.
Nobody can do remember all of these
addresses. Something has to translate the
easy to remember words into the long, hard
to remember numbers. That's why we have D.
N s. Why do we need the address? Is
because you can't route a packet through
the network using a word. It's just like
when you're driving and your GPS tells you
to turn right or go straight based on your
current position. It uses latitude and
longitude, not the name of your current
street. It's the numerical addresses that
routers use to send the packets on to
their destination. Computers are simply
faster when using numbers versus words.
DNA's is the protocol that converts these
easy to remember words that we want to use
into the numbers that routers and hosts
need. It's the connection between the
names and the actual addresses where the
services reside. Now that we've
established the need for DNS. Let's see
how it works. Gabriella works for Global
Ticket, a division of Globomantics. They
sell blocks of tickets to concerts, plays
and other events to corporations. Right
now, they're adding a new sales office and
want to document their current set up.
Using wire shark later will help their
staff configure the new offices DNA s and
then test and troubleshoot everything at
the packet level. Gabriella works in the
help desk and supports everyone who books
the bands for the concerts that Global
ticket presents. She'll be capturing the
traffic to demo. How everything works from
the client side. Let's start with a simple
DNA's query to a local server. It's always
best to start with success, so we know
what things are supposed to look like. The
sales people at global ticket work, with
corporations to book events or by blocks
of tickets for their customers. It's their
job to enter the information into the
sales application. Gabriella is going to
install wire shark onto one of their
machines so she can document the process.
This will be a successful query, and the
server will have the correct information
on its hard drive. Later in the course
will discuss how the workstation knew where to send the DNS query