- [Narrator] Packet analysis is a primary way
of monitoring your network.
Computer network professionals use packet analysis
to observe and diagnose the health of a network.
Cybersecurity professionals use packet analysis
to conduct passive network vulnerability assessments.
The adjective passive, here means that
whoever is inspecting the packets doesn't take
any actions affecting them like dropping the packets
or altering them.
Attackers use packet analysis, as a passive attack tool
to steal information such as passwords.
The term, Packet in packet analysis is misleading
because frames are what's actually captured and analyzed.
Think of frames as container trucks
delivering network packets in a local area network or WLAN.
Intercept a frame and take a packet out of it
for further inspection.
To give you an analogy I can use
the example of a Russian doll.
Let's say that the outer most shell is a frame,
within the frame you see a packet housed
and then within the packet we have application
or other protocol information.
Packet analysis results always mention frames
and provides frame details in addition to
the packet information.
A packet also carries data used by various network protocols
such as TCP, UDP, IP, ARP, HTTP, et cetera.
TCP stands for Transmission Control Protocol,
UDP stands for User Datagram Protocol.
TCP and UDP govern how reliably a packets travel
through the internet between their sources and destinations.
ARP stands for Address Resolution Protocol
which helps with translation between the IP addresses
and physical or ethernet addresses.
We'll have a chance to discuss ARP more in depth
in the next lesson.
Packet analysis need for inspecting protocol details
delivered by packets and a relevance to networking
and cyber security are why packet analysis is also called
Protocol analysis.
Packet analysis is an essential element of any network
or cybersecurity professional's tool box.
It's indispensable in many different context
of network trouble shooting
and cybersecurity investigations.