In this video,
we're going to discuss various software tools
that are used in troubleshooting
and configuring our networks and network devices.
This includes wifi analyzers,
protocol analyzers and packet captures,
bandwidth speed tests, port scanners,
NetFlow analyzers, and IP scanners.
First, we have wireless analyzers,
which is a specialized piece of software
that can be used to conduct wireless surveys
to ensure you have the proper coverage
and it helps you prevent any non-desired overlap
between wireless access point coverage zones
and channels.
Now, if you're concerned with the channels in use
and their signal strength for a given area,
you can use a view inside of a wifi analyzer
to display the SSID of each network detected in that area,
their relative signal strength,
and the channel they're using.
Here, you can see that most
of the 2.4 gigahert wifi networks
are in use and are centered on channel one,
with four others being located on channel six.
Now, channel 11 is not being heavily utilized at all.
It only has one network called home.
This is being located on Channel 11 as the home network,
but there are four other wireless networks
located at channel nine, and this could cause interference
for both channel six and channel 11,
as you can clearly see their overlapping frequencies
on this visualization.
Now, in addition to this view,
you can also overlap the coverage zones on a floor plan
using a wifi analyzer as part of a wireless site survey.
This displays the location of the wireless access points
and the signal strength
that's radiating from each of those access points.
In this example, you can see the entire office building
is pretty well covered in wifi
as it's shown by the green coverage areas,
but there is a small area of yellow and orange
on the leftmost wall.
As you exit the building,
you'll see more areas of orange and red,
which indicates areas of lower signal strength too.
Due to the left wall
having a large orange and yellow coverage area,
we may want to suggest adding another access point
in this area of the building.
This would allow us to have more
wireless networking capabilities
on that part of the building if we needed to.
Next, we have protocol analyzers and packet capturing tools.
Now, a protocol analyzer is used to capture
and analyze signals and data traffic
over a communication channel.
In networking, we most commonly use a software tool
known as Wireshark as a protocol analyzer.
Now, a packet capturing tool
is going to be used to capture packets running
over a network connection in real time,
and then save them for later analysis.
This lets you intercept,
log and analyze the network traffic and data
in order to fully identify, classify,
and troubleshoot network traffic
based on its application type, source, and destination.
A tool like Wireshark contains both a protocol analyzer
and a packet capture functionality,
making it a great all-in-one tool for you to use.
Now, Wireshark and other protocol analyzers
are going to be used to troubleshoot your networks
when they're experiencing performance issues.
By using Wireshark, you can see a breakdown of each packet
that's flowing across the network,
and you can validate if things are operating
as they should inside your network.
Cybersecurity professionals also use Wireshark
and other packet captures and protocol analyzers
to be able to trace connections,
view the content of suspected network transactions,
and identify bursts of network traffic as either suspicious,
malicious, or benign.
In addition to Wireshark,
there are many other protocol analyzers
out there in the field, including Ethereal,
Protocol Expert, Netasyst, Network Analyzer,
Network Instruments Observer,
LANHound, and EtherPeek.
As for packet capture or packet sniffing tools,
Wireshark can also perform this function,
but so does tcpdump, WinDump, PRTG network monitor,
SolarWinds Network Performance Monitor, and NetworkMiner.
Next, we have bandwidth speed testing tools.
There are several local area network speed test tools
that exist, and there's also many websites
that will allow you to conduct an end-to-end speed test
from your client to their internet servers.
Now, a bandwidth speed test tool
should be more accurately described
as a throughput test tool though because remember,
real-world throughput is the speed from your client
to the endpoint device and back,
whereas bandwidth is the theoretical limit.
Essentially, these tools are going to download
a large random file from a server,
and then turn around and upload it back to that same server.
During this download and upload process,
the server measures the amount of time it took
to download that file and then upload it again.
This gives you a real-world measure of the throughput
across your network from the client
all the way to that server.
Now, a local area network version of this
is going to do the same exact thing,
but it's going to be conducted by a network appliance
or a piece of software that you connect to the network.
This type of speed test works much the same way
as the internet speed test I just described,
except your data transfer only occurs
over the local area network
from one client to another client,
measuring the time it takes to send and receive
that test file locally.
If you need to determine if your internet connection
is performing adequately,
you can use an internet bandwidth speed test
like speedtest.net.
If you need to determine if your local area network
performance is adequate,
then you're going to use a local area network version of this,
something like LAN Speed Test or HELIOS LanTest software
to meet this need.
Next, we have port scanners.
A port scanner is a software tool
that's used to determine which ports are open on a network.
Running a port scan on a network or server
is going to reveal which ports are open and listening
or ready to receive information,
as well as revealing the presence of security devices
such as firewalls that may be present between the sender
and the target.
Now, a port scan can send a carefully prepared packet
to each destination port,
and then analyze the response it receives back
to determine if that port is open, closed, or filtered.
Now, there are many different software-based
port scanning tools available.
One of the most common is Nmap: the Network Mapper,
but there are lots of others out there as well,
including the SolarWinds Port Scanner and Lansweeper.
Next, we have NetFlow analyzers.
A NetFlow analyzer is a software tool
used to perform monitoring, troubleshooting,
in-depth inspection, interpretation,
and synthesis of traffic flow data.
By analyzing NetFlow data,
you can more accurately conduct capacity planning
and ensure that resources are being appropriately used
in support of your organizational goals.
For example, using NetFlow data,
we can see what types of traffic
is consuming all the resources on a network.
Is most of your bandwidth
being used by people going on Facebook?
How about Twitter?
What about Gmail or Exchange?
Depending on your organizational requirements,
you may not want a lot of your bandwidth being used
by people browsing social media,
but if you're a social media marketing company,
you would expect to have a large number of people
on Facebook all day work,
and that would be completely appropriate.
By using NetFlow, you're going to be able to see that traffic
and determine what looks right to you.
Now, in addition to looking at specific websites being used,
you can also look at the application type
that's generating that traffic,
such as web, NetBIOS, voiceover IP services,
ICMP, or even BitTorrents.
By understanding the data flows in your network,
you can increase your overall performance
or even block traffic types
that are not generating any value for your business.
Lastly, we have IP scanners.
An IP scanner is a software tool
that's used to search for and detect IP addresses
and other information related to devices on your network.
These tools are going to be used to conduct network management
and to identify any rogue devices
that may be connected to your network.
There are many IP scanners available for us,
including Nmap: the Network Mapper,
Free IP scanner, IP Address Manager,
PRTG Network Monitor, Angry IP Scanner, Network Scanner,
and the IP Range Scanner by Lansweeper.
As you may have noticed,
many of these IP scanners are the exact same tools
as we discussed for port scanners,
or at least made by the same companies.
Now, this is because like Nmap,
many of these tools can first scan for the IP addresses
on your network segment,
and then they can conduct a deeper scan
against each of those IP addresses
to scan the ports and the services over those ports.
For the exam, it's important for you to understand
when you might use a wifi analyzer,
a packet analyzer, a packet capture tool,
a bandwidth speed test tool, a port scanner,
NetFlow analyzers, or an IP scanner.
If you can remember which tool is used for which thing
in your network management and troubleshooting,
you're going to do fine on test day,
but you do not have to remember all the names
of all these tools.
The only ones you'll probably need to know by name
are things like Nmap and Wireshark
because those are so heavily used
in network troubleshooting.