Student Name: ___________________________
CHABOT COLLEGE
CISCO NETWORKING ACADEMY I
9A - IP ADDRESS FUNDAMENTALS
Directions: Complete all tables on this worksheet.
Use Chapter 10 as a reference.
Step 1 – Review IP Address classes and their characteristics:
1st Octet
Cls Decimal
Range
A 1 – 126*
B 128 – 191
1st Octet
High
Order
Bits
0
Network /
Default Subnet
Host ID
Mask
(N=Network
, H=Host)
N.H.H.H
255.0.0.0
Number of
Networks
Hosts per Network
(usable addresses)
126 (27 – 2)
16,777,214 (2 24 – 2)
10
N.N.H.H
255.255.0.0
16,382 (214 - 2)
255.255.255.0
2,097,150 (2 – 2) 254 (2 8 – 2)
C 192 – 223
D 224 – 239
110
N.N.N.H
1110
Reserved for Multicasting
E 240 – 254
11110
Experimental, used for research
65,534 (2 16 – 2)
21
* Class A address 127 cannot be used and is reserved for loopback and diagnostic functions
Reminders: "Octet" means 8 bits.
The host portion of a valid address cannot be entirely:
 0s (decimal 0s) This address is reserved for the network itself.
 1s (decimal 255s) This address is reserved for broadcasts on the network.
Step 2 – Address examples.
In the following table, enter a valid example of a host address from each of the three classes:
CLASS
IP Address Example
(use dotted decimal format)
A
B
C
Step 3 – Determine the host and network portion of the IP address.
Complete the following table, using the labels Net and Host to indicate which octets represent
those portions of the address. Also indicate the default subnet mask in dotted decimal format:
CLASS
Octet 1
Net or Host?
Octet 2
Net or Host?
Octet 3
Net or Host?
A
B
C
1
Octet 4
Net or Host?
Default Subnet Mask
(use dotted decimal format)
Student Name: ___________________________
Complete the following table, using these guidelines:

For the network address, the host portion will be all zeros.
(Example: for the Class C address 209.23.145.19, the network address is 209.23.145.0)

For the broadcast address, the host portion will be all ones.
(Example: for the Class C address 209.23.145.19, the broadcast address is 209.23.145.255)

For the default subnet mask, the network portion of the address will be all ones and the host
portion will be all zeros.
(Example: for the Class C address 209.23.145.19, the default subnet mask is 255.255.255.0)
Host IP Address
Addr.
Class
Network Address
Network Broadcast
Address
Default Subnet Mask
216.14.55.137
123.1.1.15
150.127.221.244
194.125.35.199
175.12.239.244
Step 4 – Determine which IP host addresses are valid for commercial networks.
For the following IP host addresses, determine which are valid for commercial networks.
For each, explain why it is valid or not.
Valid means it could be assigned to a workstation, server, printer, router interface etc.
The network and broadcast addresses are not valid for workstations, servers, etc.
IP Address
Valid Address? (Yes/No)
Why or why not?
150.100.255.255
175.100.255.18
195.234.253.0
100.0.0.23
188.258.221.176
Step 5 – Determine IP addresses characteristics for operating commercial networks.
Ping each of the following URLs.
The ping command will show the host IP address, which will allow you to complete the table.
Website
Host IP Address
Addr.
Class
Network Address
www.cisco.com
www.yahoo.com
www.chabot.cc.ca.us
www.berkeley.edu
END | THREE-HOLE PUNCH | STAPLE | SUBMIT
2
Network Broadcast
Address