Question

COMPUTER NETWORKS:

1.   An organization with a Class B IP address of 128.25.0.0/16 wants eight subnets in its network. There are some legacy routers. Hence, they do not want to use zero and all-ones subnets.

a.   How many bits are used in each of the following three fields?

netID: ______________       subnetID: __________   hostID: _________________

b.   Determine the subnet mask that needs to be set in the hosts in dotted decimal notation.

Subnet Mask in dotted decimal notation: ¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬_______________________________________

c.   Given that the class B address is 128.25.0.0/16, determine the network and broadcast addresses for subnet numbered 5.

Network address for subnet 5: ________________________________________________

Broadcast address for subnet 5: _______________________________________________

d.   Determine the range of assignable IP addresses for hosts in this subnet.

Range of assignable IP addresses: _____________________________________________

2.   An ISP requested 500 and was assigned 512 Class C addresses in the range 192.64.10.0 to 192.64.11.255.

a.   Determine the number of bits are used in the netID and hostID portions for this supernet of the two Class C addresses.

netID: ______________                       hostID: _________________

b.   What is the network address for this supernet?

Network address for the supernet: ____________________________________________

c.   What is the broadcast address for this supernet?

Broadcast address for the supernet: ___________________________________________

d.   What is the subnet mask to be set in the hosts in this supernet?

Subnet Mask in dotted decimal notation: ¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬_______________________________________

3.   Consider an organization that needs 400 IP addresses. The organization has been assigned two blocks Class C addresses. 200.128.64.0 – 200.128.64.255, and 200.128.65.0 – 200.128.65.255.

a.   Given a 32-bit IP address belonging to this organization, say 200.128.64.120, how many bits represent the netID and how many bits represent the hostID?
netID: ______________                       hostID: _________________

b.   Determine the network address for this organization.

Network address: __________________________________________________________

c.   Determine the broadcast address for this organization.

Broadcast address: __________________________________________________________

d.   Determine the subnet mask to be used on routers outside this organization for this supernet.

Subnet Mask in / notation: ___________________________________________________

   Subnet Mask in dotted decimal notation: _______________________________________

Having obtained these 512 addresses, the organization decided to subnet its address space with 3 bit subnetID.

e.   Determine the number of subnets possible in this organization. The organization plans to use zero and all-ones subnets.

Number of subnets possible: __________________________________________________

f.   Determine the number of hosts possible in each subnet.

Number of assignable hosts possible in each subnet: __________________________

g.   Consider host numbered 18 in subnet numbered 4. Determine its IP address.

IP address: _________________________________________________________________

h.   Determine the subnet mask to be set on hosts and routers within this organization.

Subnet Mask in dotted decimal notation: _______________________________________

i.   For subnet numbered 4, determine the network address.

Network address for subnet 4: ________________________________________________

j.   For subnet numbered 4, determine the broadcast address.   

Broadcast address for subnet 4: _______________________________________________
4.   The College at Brockport has Class B address 137.21.0.0/16. When I used my desktop and connected to the campus network, the ipconfig command showed the following parameters:

IP Address . . . . . . . . . :   137.21.102.233
   Subnet Mask . . . . . . . . . :   255.255.255.0

When I connected a laptop, the ipconfig command showed the following parameters:

IP Address . . . . . . . . . :   137.21.152.226
   Subnet Mask . . . . . . . . . :   255.255.224.0

a.   Consider the desktop. How many bits are used in each of the following three fields?

netID: ______________       subnetID: __________   hostID: _________________

Given the above sizes of the various fields, what is the maximum number of hosts in the 137.21.102 subnet?

Maximum number of hosts on the subnet: ______________________________________   

b.   Consider the laptop. How many bits are used in each of the following three fields?

netID: ______________       subnetID: __________   hostID: _________________

Given the above sizes of the various fields for the 137.21.0.0/16 address space, how many hosts (wireless devices) can be supported on this campus?

Maximum number of wireless devices supported on this campus: ___________________

___________________________________________________________________________

5.   The College at Brockport has Class B address 137.21.0.0/16. When I connected a second laptop, the ipconfig command showed the following parameters:
 
IP Address . . . . . . . . . :   137.21.136.178
   Subnet Mask . . . . . . . . . :   255.255.224.0
   Default Gateway . . . . . . . :   137.21.159.254

   For the Brockport Wireless Subnet determine the following:

   Network address: __________________   Broadcast address: ___________________

Range of assignable IP addresses: _____________________________________________

Answer 1

When we do subnetting, we borrow bits from the host id and subnet mask also change accordingly. Broadcast address is used when we want to send packet to all the host under network. For more detailed explanation attaching image.