# CS610 Computer Network Assignment 3 Solution Fall 2013

Assignment
Question No.1 Marks 5
Given below is a list of IP addresses based on different classes of IP addresses. You are required to write the number of bits used to identify an individual computer (host) on the network, for each given IP address in the table below.

S. No  IP address                 No. of Bits for Host
1            192.168.1.1                  8 bits
2           125.167.2.1                  24 bits
3           189.165.3.1                  16 bits
4           201.164.4.1                  8 bits
5           129.153.5.1                  16 bits
Question No. 2 Marks 5
Suppose an ISP has an IP address 128.13.190.11/26. You have to find the following:
a. Number of usable hosts (with complete calculation).

Solution: Number of usable hosts will be 62
b. Subnet Mask (No calculation required).
Calculation No. of Usable Hosts

Solution:

128.13.190.11/26. means there are 6 zero’s i.e.

1111111 11111111 11111111 11000000

According to the below formula

11111111=255

and 11000000=192

128+64=192

255 255 255 192

 128 64 32 16 8 4 2 1 1 1 0 0 0 0 0 0

So