computer network questions
CSE 4344/5344: Computer Networks
Summer 2022
Homework
Due Date: August 11 (12:00 noon), 2022
Full Points: 100
Instruction:
– You can use multiple resources but you must answer each questions in
your own words. If anything found copied, everyone involved will be
penalized -100.
– Show detail of the work for each problem.
– Submit your answer in pdf format (Canvas will not accept any other
format)
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Q 1: Consider a datagram network using 32-bit host addresses.
Suppose a router has four links, numbered 0 through 3, and
packets are to be forwarded to the link interfaces as follows:
Destination Address Range
Link Interface
11100000 00000000 00000000 00000000
through
11100000 00111111 11111111 11111111
0
11100000 01000000 00000000 00000000
through
11100000 01000000 11111111 11111111
1
11100000 01000001 00000000 00000000
through
11100001 01111111 11111111 11111111
2
otherwise
3
Describe how your forwarding table determines the appropriate link
interface for datagrams with destination addresses: (10 Points)
11001000 10010001 01010001 01010101
11100001 01000000 11000011 00111100
11100001 10000000 00010001 01110111
Q 2: Consider a router that interconnects three subnets: Subnet 1,
Subnet 2, and Subnet 3. Suppose all of the interfaces in each of
these three subnets are required to have the prefix 223.1.17/24.
Also suppose that Subnet 1 is required to support at least 60
interfaces, Subnet 2 is to support at least 90 interfaces, and Subnet
3 is to support at least 12 interfaces. Provide three network
addresses (of the form a.b.c.d/x) that satisfy these constraints.
(15 Points)
Q 3: Consider a subnet with prefix 128.119.40.128/26. Give an
example of one IP address (of form xxx.xxx.xxx.xxx) that can be
assigned to this network. Suppose an ISP owns the block of
addresses of the form 128.119.40.64/26. Suppose it wants to
create four subnets from this block, with each block having the
same number of IP addresses. What are the prefixes (of form
a.b.c.d/x) for the four subnets?
(15 Points)
Q 4: Consider the topology shown in following figure. The three
subnets with hosts are denoted as Networks A, B, and C. And the
subnets without hosts are denoted as Networks D, E, and F.
(20 Points)
Subnet A
Subnet F
Subnet D
Subnet E
Subnet C
Subnet B
Assign network addresses to each of these six subnets, with the
following constraints:
All addresses must be allocated from 214.97.254/23;
Subnet A should have enough addresses to support 250 interfaces;
Subnet B should have enough addresses to support 120 interfaces;
and
Subnet C should have enough addresses to support 120 interfaces.
Of course, subnets D, E and F should each be able to support two
interfaces. For each subnet, the assignment should take the form
a.b.c.d/x or a.b.c.d/x – e.f.g.h/y.
Q 5: Consider sending a 2400-byte datagram into a link that has an
MTU of 700 bytes. Suppose the original datagram is stamped with
the identification number 422. How many fragments are generated?
What are the values in the various fields in the IP datagram(s)
generated related to fragmentation?
(15 Points)
Q.6. Suppose we are creating classless networks (using VLSM) for
the network depicted in the following diagram with a class C
network 192.168.10.0/24.
(15 Points)
Net A
10 users
Net B
10 users
Net C
6 users
Net D
30 users
List subnet for each networks under each site. Do not forget to
write for the two WAN links.
Example: Let’s say, a network (Net XYZ) requires subnetting with
/30, and since the given network ID is of class C, you need to write
following for NetXYZ:
Net XYZ requires /30 and the corresponding subnet mask is:
255.255.255.252
Q.7. For the following diagram, find the summarized route that the
router R1 will forward to the router R2. Show detail of your work
and express the summarized route in CIDR format. (10 Points)