Module 1 Lab #1: System Discovery

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Oct 24, 2013 (3 years and 7 months ago)

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Module
1

Lab #1
: System Discovery

Name: _______________________________________ Section: _________________

Objective

The purpose of this lab is to introduce you to the m
ethods for discovering your com
puter’s
network connection, host name, MAC (Layer 2)

address and network (Layer 3) address.

Scenario

This lab assumes you are using any version of Windows. You will go out and see your
system’s host name, MAC address and network address. This is a non
-
destructive lab and
you should be able to do it with you
r home machine without concern of changing your
system configuration.

Ideally, this lab will be done in a classroom or other LAN
with multiple computers
connected to the Internet



even a home LAN
.

Part 1

Use the Start menu to open the Command Prompt (DOS
-
like) window (Start | Pro
-
grams |
Accessories | Command Prompt or Start |
Run and type
cmd

Press Enter
.


Type ipconfig and press E
nter

while in the command window. The following figure shows
the Command screen. Ipconfig spelling is critical while case i
s not.


This first screen shows the IP address, subnet mask, and the default gateway. You should
find that the IP address and the default gateway are in the same network or sub
-
net,
otherwise this host wouldn’t be able to communicate outside the network.
In the figure the
subnet mask tells us that the first three octets must be the same to be in the same network.


Note:

If you are on a LAN, you might not see the default gateway if you are running
behind a Proxy Server.


Write down your IP address: ________
________________________________


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Write down your Subnet Mask: ______________________________________


Write down your Default Gateway: ___________________________________

Part 2

If you are doing this on a LAN, compare the information of several machines.

Are there any similarities? ______________________

What are similar about the IP addresses? _______________________________

What are similar about the default gateways? ____________________________

The IP addresses should share the same network portion. Al
l machines in the LAN should
share the same default gateway.

Recor
d a couple of the IP Addresses?
__________________________________

__________________________________________________________________

Part 3

To see more info, type ipconfig /all and press EN
TER. The figure shows the detailed IP
configuration screen.


You should now see the host name (computer name, NetBIOS name), the DHCP server’s
address, if used, and the date the IP lease start
s and ends. Look over the infor
mation. You
may see entries for
a DNS server, which are used in name resolution.

Do all of the servers share the same network portion of the IP address as your work
-
station? It would not be unusual for some or all to be in another network. It means that your
default gateway is going to
forward (route) your requests to the other network.

The above figure reveals that the router is also performing DHCP and DNS services for this
small network


this would be a small office / home office (SOHO) or small branch office
implementation.

We also
see the Physical Address (MAC) and the NIC card model (Description).

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In the LAN, what similarities do you see about the Physical (MAC) Addresses?

_____________________________________________________________________

While not a requirement m
any

LAN adminis
trators try to standardize components like
NICS

or computer models with built
-
in NICs
, so it would not be surprising to find all
machines share the first three Hex pairs in the adapter address. These three pairs identify
the manufacturer of the adapter.

Wr
ite down the IP addresses of any servers listed: _____________________________

______________________________________________________________________

Write down the computer’s Host Name: ______________________________

Write down the Host Names of a couple
other computers: _______________________

______________________________________________________________________

Close the screen when you are through looking around
. Repeat the above steps as nec
essary
to make sure that you can return to and interpret this

screen.

Reflection

Based on what you observed today, what can you deduce about the following results taken
from three computers connected to one switch?

Computer 1

IP Address: 192.168.12.113

Subnet Mask: 255.255.255.0

Default Gateway: 192.168.12.1

Comp
uter 2

IP Address: 192.168.12.205

Subnet Mask: 255.255.255.0

Default Gateway: 192.168.12.1

Computer 3

IP Address: 192.168.112.97

Subnet Mask: 255.255.255.0

Default Gateway: 192.168.12.1

Should they be able to talk to each other


are they all on the
same network? Why or why
not? If something is wrong, what is most likely the problem?

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Module
1

Lab
#
2: Connectivity Tools

Objective

In this lab you will learn to use the TCP/IP Packet Internet Groper (Ping) and Trace Route
(Tracert) commands for testing co
nnectivity in a network. In the process you will see name
resolution occur using one or more DNS servers.

Scenario

This lab assumes you are using any version of Windows. This is a non
-
destructive lab and
you should be able to do it with your home machine w
ithout concern of changing your
system configuration.

Ideally, this lab will be done in a classroom or other LAN connected to the Internet. You
will need the IP addresses that you recorded in Lab 1.

Part 1

Use the Start menu to open the Command Prompt wi
ndow.

T
ype ping followed by the IP address of your computer


you wrote it down on the last
exercise. The following figure shows the possible result of pinging your own IP address.


Ping uses the ICMP “echo reply” feature to test
connectivity. Since it re
ports on four
attempts
,

you
have
an indication of the reliability of the connection. Look over your results.

Note:
Windows 7’s firewall may prevent the pings from returning


appear to fail.

Try pinging the default gateway’s IP address if one was listed in

the last exercise. If you
can, it means you have physical connectivity to the router on your network and therefore
probably the rest of the world.

If you are in a classroom or working with a second computer on the network, try pinging
the IP address of an
other machine. Note the results. Try others in the LAN.

Try pinging the IP address of the DHCP and/or DNS servers listed in the last exercise. If it
works for either server and they are not in your network, what does that tell you? It means
your router is
functioning as a default gateway to get you out.

Were you successful? ________________

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Part 2

Try pinging 127.0.0.1 although it can be any 127 address. The 127 network is reserved for
loopback testing. If you can successfully ping the loopback address you
know that TCP/IP
is properly installed and functioning on this computer.

Were you successful? ________________

Part 3

Try pinging
www.abc.com
.


The first line of output shows you the Fully Qualified Domain Name (FQDN) followed by
the IP address. A (Domain

Name Service) DNS server somewhere out in the net
-
work was
able to resolve the name to an IP address. DNS servers resolve Domain names (not host
names) to IP addresses.

Without this name resolution, the ping would have failed because TCP/IP only under
-
st
ands valid IP addresses


not names. You would not be able to use your Web browser
without this name resolution.

With DNS you can verify connectivity to computers on the Internet using familiar Web
addresses (domain names) without having to know the actual

IP address. If the nearest
DNS does not know the address, it will ask a Server higher in the Internet structure.

Part 4

Try pinging
www.microsoft.com
.


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Notice that the DNS server was able to resolve the name to a
n IP address, but you get no
response. Microsoft routers have been configured to ignore ping requests. This is a security
measure that many networks implement

today
.

Try to ping several other domain names
including
www.washington.edu

(or
www.uw.edu
)
and
www.ischool.washington.edu

that
you are aware of and record the results:

Example: www.msn.de IP: 207.46.28.116 Successful 4 times

__
____________________________________________________________________

______________________________________________________________________

______________________________________________________________________

_____________________________________________
_________________________

Part 5

Try typing
tracert www.cisco.com

and press ENTER.


Tracert is TCP/IP’s abbreviation for trace route. The preceding figure shows the possible
result when running tracert from Bavaria in Germany. The first line of output sho
ws you
the Fully Qualified Domain Name (FQDN) followed by the IP address. So we know that a
DNS server was able to resolve the name to an IP address. Then there are listings of all
routers the
T
racert requests had to pass through to get to the destination.

Tracert actually uses the same echo requests and replies as the ping command but in a
slightly different way. You should see that Tracert actually contacted each router three
times. By comparing the results we can gauge the consistency of the route. Notic
e in the
above example that there were relatively long delays after router 11 and 13, possibly due to
congestion. The main thing is that there seems to be relatively consistent connectivity.

Each router represents a point where one network connected to ano
ther and your packet
was forwarded through.

Note:

If you get a couple rows of stars, the destination device has probably been
configured to not reply to PINGs. Press
[Ctrl]+c

to stop the command.

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Part 6

Try tracert on other domain names or IP addresses
lik
e Yahoo
and record the results:

Example: www.msn.de IP: 207.46.28.116 It is 14 hops (routers) away

______________________________________________________________________

______________________________________________________________________

______________
________________________________________________________

______________________________________________________________________

Part 7

In this next exercise, we will use t
he
nslookup

c
ommand

and DNS feature to find the IP
address
(es)

for a domain name or a
ny domain names associated with an IP address.

Either
way
a domain name query packet
is sent
to a designated (or defaulted) DNS server

for
resolution. An example of each form:

C:
\
>
nslookup www.cisco.com

Server: ns11.attbi.com

Address: 204.127.199.8


Non
-
authoritative answer:

Name: www.cisco.com

Address: 198.133.219.25


C:
\
>
nslookup 198.133.219.25

Server: ns11.attbi.com

Address: 204.127.199.8


Name: www.cisco.com

Address: 198.133.219.25


C:
\
>

Note:

Many searches by IP address will fail because of

company security implementations.

In the command window, tr
y
:

nslookup www.ischool.washington.edu

What is the IP address(es)? __________________________________________________

nslookup 207.200.74.2

What is the Domain Name? _______________________________
___________________

Try any domain names you like and record the IPs.

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Module 1 Lab #3:
Binary to Decimal Conversion


Objective

In this exercise you will practice converting binary values to decimal values.

Back ground

Binary data is made up of ones and ze
ros (on and off). While binary data can be grouped in
varying increments like 3 or 4 digits (110 or 1011), in TCP/IP it is usually grouped in eight
digit groups called a Byte.

A Byte (8 bits) can range from 00000000 to 11111111 creating 256 combinations wi
th
decimal values ranging from 0 to 255. IP addressing uses 4 bytes (32 bits) to identify both
the network and specific device (node). The example at the top of this lab is an e
x
ample of
an IP address in both binary dec
i
mal formats.

A simple tool for easil
y converting Binary to Decimal values is the following table. The
first row is created by counting right to left from one to eight for the basic eight bit
p
o
sitions (although it would work for any size binary value). The value row starts with one
and doubl
es (base 2) for each position to the left.


Steps

1.

Type the binary bits (for example 10111001) in row three.

2.

Put the decimal values in row four only for the third row 1s. Technically the row two
values are being mult
i
plied by row three.

3.

Now just sum row f
our (across).


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Practice

Convert the following binary values to decimals:

1)

1110

_______________________

2)

100110

_______________________

3)

11111111

_______________________

4)

11010011

_______________________

5)

01000001

_______________________

6)

11001110

_______________________

7)

01110101

_______________________

8)

10001111

_______________________

9)

11101001.00011011.10000000.10100100

_____._____._____._____

10)

10101010.00110100.11100110.00010111

_____._____._____._____

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Module 1 Lab #4
: Decimal to Binary conversion


Objective

In this exercise you will practice converting decimal values to binary values.

Back ground

A simple tool for easily converting Binary to Decimal values is the fo
l
lowing table. The
first row is created by counting
right to left from one to eight for the basic eight bit
p
o
sitions (although it would work for any size binary value). The value row starts with one
and doubles (base 2) for each position to the left.


The same conversion table and simple division can be u
sed to convert Decimal values to
Binary.

Steps

Say we want to convert 207 to binary.

1.

Start with left
-
most value (largest) and see if the decimal value can be d
i
vided by it.
Since it will go once, we put a 1 in row three of the conversion table and calc
ulate the
remainder (79).

2.

Since the remainder can be divided by the next value (64), put a 1 in row
three of the table.

3.

Since the remainder cannot be divided by either 32 or 16 we put 0s in
row three of our table.

4.

We continue until there is no remainder.

5.

If necessary, use row four to check your work.


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Practice

Convert the following decimal values to binary:

1)

123

_______________________

2)

202

_______________________

3)

67

_______________________

4)

7

_______________________

5)

252

_______________
________

6)

91

_______________________

7)

116.127.71.3

___________.___________.___________.___________

8)

255.255.255.0

___________.___________.___________.___________

9)

192.143.255.255

___________.___________.___________.___________

10) 12.101.9.16

_
__________.___________.___________.___________