Networking Fundamentals: IPv4 Addressing and Routing Protocols

Desklib provides solved assignments and past papers to help students succeed.

ASSIGNMENT 2

Q1. What are the differences between classful and classless addressing in IPv4?
The major dissimilarity between classless and classful addressing is that the allocation of IP addresses is
more effective and efficient in classless addressing as compared with the classful addressing.
As per Ranjit et al. (2019), Classful addressing is a type of allocation method for IP addresses which is
done majorly with five classes. While classless addressing is a type of allocation method for IP addresses
which is designed basically for the purpose of replacing the classful addressing, this is done to decrease
the speedy exhaustion in the IP addresses. Also, the classless addressing is more beneficial and valuable
than the classful addressing.
Now in classful addressing, the host and network ID varies or changes in accordance with the classes.
While in the case of classless addressing, the host and network ID has no barrier.
Q2. Explain why most of the addresses in class A are wasted. Explain why a medium or large size
organization does not want a block of class C.
Falling in the category of classful addressing, class A is a subnet with addressing worth of 24 bits; this
makes the network scheme very vast in which around 16 million interfaces of networks are used for
storing the addresses. According to Pederzolli et al. (2019), it becomes very hard for any organization to
use this scheme of addressing in which most of the addresses remain empty or unused. Class C is a 32-bit
scheme of IPv4 addressing, which is very small for the organizations of large and medium size. Also
only, 256 number of address are available as actual addresses. From the 256 addresses in class C block,
only 254 addresses are usable. The 255th address of the host in block C is used as the address of broadcast,
anything allocated in this 255th address must be answered with all the devices available in the identical
block of IP.
Q3. What is a mask in IPv4 addressing?
Boucadair et al. (2019) said that a mask or bitmask in computer science is the information and data which
is used for the operations that are based on the bitwise, especially in the bit field. With the usage of a
mask, multiple bits in a word, byte, nibble, etc. can be either set to be off/on or can be turned to on/off in
particular operation of bitwise. Mask in IPv4 addressing is also known as CIDR or slash notation. For
example, in x.y.z.t/n, here ‘n’ is the mask. Mask in classless addressing can take any value from 0-32.
Masking Is done basically to separate the address of host and address. This ensures network stability even
at the time of heavy traffics.

Q4. What is the network address in a block of addresses? How can we find the network address if
one of the addresses in the block is known?
In a block of addresses, a network address is the first address. In the words of Menon et al. (2019), The
network address works as the identifier for any host or a node on a network of a telecommunications.
Addresses of networks are generated and designed for the purpose of acting as unique identifiers across
any network. Also, a network address is a physical or logical type of address that distinguishes a device or
a node of network uniquely. Now for the purpose of finding the first address in a network address either it
is classless or classful address, the address available at the first place must be divisible evenly by the
number of address numbers. For example, if 6 addresses are present in a block, the address in the first
position must be divisible by 6.
Q5. Briefly define subnetting. How does the subnet mask differ from a default mask in classful
addressing?
According to Yoakum et al. (2015), There are mainly two components in an IP address, host address, and
the network address. A subnet mask in IPv4 addressing helps to separate out the host address and network
address. For the purpose of masking an IP address, the subnet mask is used which is a 32-bit number.
Also, the subnet mask provides bitwise AND operation for identifying the address of a network on the
netmask. The separation of host and network address is done by allocating 1’s to the network bits and 0’s
to the host bits. Furthermore, the subnetting of an IP network is done to divide a large network in multiple
networks of smaller size for the purpose of security and reorganization. Also, the classful addressing uses
the default subnet mask in which the IP address assuming is done. The classful addressing faces problems
for the addresses of IP where default subnet masks are absent (Liu & Kawashima 2019).
Q6. What is NAT? How can NAT help in address depletion?
As per Wijaya (2011), NAT stands for Network address translation, which is basically a remapping
method of an IP address space to a different by enhancing or reshaping the network address data in the
packets of IP header at the time of passage through a routing device. For the purpose of avoiding the
readdressing task in each host separately at the time when a network is moved, this technique was
introduced to do this task in a shortcut manner. The NAT has become an essential popular tool which is
highly valuable and useful for the users. Furthermore, for a whole private network, one gateway of NAT
can be used. Implementations of NAT vary very widely in accordance with their specific behavior in
different cases of addressing. Also, the connectivity of the internet faces some issues while applying

NAT.
Q7. What is the difference between connection oriented and connection less services?
The connection oriented services are shaped by following the system of the telephone while the
connectionless services are shaped after the posted system. Onursal & Sari (2019) said that the connection
oriented services receive and gather the data by the identical order as it was sent while in the
connectionless services, the messages and information can be received or gathered in a dissimilar order as
it was sent with. Also, the connection oriented services are more reliable and acknowledged as compared
to connectionless services. The connection oriented services require authentication but it guarantees the
delivery which is based on stream, while the connectionless services don’t require authentication also it
does not provide any kind of guarantee for the delivery which is based on the message.
Q8. Define fragmentation and why it is needed?
The term fragmentation tells about the status of a disk in which bifurcation of files is done over the disk.
By using the disks continuously and frequently for the purpose of modifying, deleting and creating the
files, fragmentation naturally occurs. At certain points, the storing of parts is done in the operating system
which is stored in a cluster form. The process is invisible to the users completely, but this can lower down
the processing of data speed because the various parts of the disk are searched for putting together a
particular single file. Due to retransmissions did excessively by the IP fragmentation, packet loss is
encountered which needs to be recovered from the single fragment loss. Hence, this is why fragmentation
is needed (Warsame & Sevin 2019).

Q9. List transition strategies to move from IPv4 to IPv6. Explain the differences between tunneling
and dual stack strategies during the transition period
There are several transition strategies that are used for moving IPv4 to IPv6:-
 Dual stack - This method is the simplest for transitioning IPv4 to IPv6
 Tunnelling - Generic routing encapsulation protocol is used as a major component in this
transition strategy.
 Translation - Encapsulation of packets is not done in this transition strategy rather it is
transformed into a type of destination.
As per Fiumano et al. (2019), in the tunnelling transition strategy, encapsulation of packet is done by
converting it into a wrapper. After this, transportation of the wrapper is done from a destination source
where it gets retransmitted and decapsulated accordingly. While in the dual stack, all the nodes of IPv4
and IPv6 are enabled. This is important especially at the router which acts as the node first for a network
given to gather traffic that is coming from outside network.
Q10. What are some common address mapping protocols and in which scenario would you use
each?
Lima et al. (2019) said that belonging to the category of communication protocol, Address resolution
protocol is used for the purpose of addresses of link layers like MAC address. There are several Address
resolution protocols which are mainly used:-
 Inverse Address Resolution Protocol (InARP) - This protocol is the expansion of address
resolution protocol which is taken into consideration by the frame relay.
 Reverse Address Resolution Protocol (RARP) - In this, the internet protocol address is requested
by the client computer.
 Gratuitous Address Resolution Protocol (GARP) – This protocol is used for the scenarios where
the advanced network is required.
 Proxy Address Resolution Protocol (PARP) – with this protocol, all the queries related to the
address resolution protocol is answered.

Q11.What is ICMP and why do we need it?
For the purpose of reporting management and error queries, internet control management protocol
(IMCP) is used. IMCP is basically a protocol of supporting, used by the routers for the purpose of sending
information of operations and messages of errors. Rather than a transport protocol, IMCP just transfers
the data and information between systems. The need for an ICMP is very crucial since IP lacks a
mechanism for sending the information of operations and messages of errors. Internet control
management protocol also provides troubleshooting service. In operating systems, IMCP is used
frequently where it transmits the messages of error in networked computers. Also, Internet control
management protocol is always combined with internet protocol (IP). Along with this, response and
request of echo are the two codes of operation used by the IMCP for the purpose of implementing ping
(Yoakum et al. 2019).
Q12.What is an autonomous system?
Abboud et al. (2019) said that supervised and managed by an organization or from a single entity, an
autonomous system is a collection of networks or a single network. Also controlled by a huge enterprise,
an autonomous system (AS) is usually a heterogeneous network. An autonomous system has many
dissimilar and different subnetworks with common policies of routing and routing logic. Each and every
subnetwork is allotted by an identification number of 16 digits which is unique globally. Also,
identification numbers are provided by the Inter Assigned Numbers Authority (IANA). For the purpose of
regulating organizations like government bodies and educational institutions, Autonomous systems were
introduced. Different networks were used to build these systems but are monitored by only a single entity.
With the usage of the Border Gateway Protocol, different autonomous systems are addressed by the
routing of packets.
Q13. What is the purpose of RIP?
As per Boucadair (2019), Routing information protocol (RIP) falls in the category of the dynamic
protocol which is used to discover the most appropriate path or route from a source to a target network by
applying the algorithm of routing count. This algorithm whose purpose is to find out the best appropriate
path form a source to a target network, hence the information is delivered in the shortest time with the
highest possible speed from node to node. Hop is the next step towards the upcoming device which can be
a computer, router or any other kind of device. After this, the hop length is found for the purpose of using
it for the future in the form of a table of routing. The routing information protocol is used for both wide

and local area networks and is assumed to be easily implemented and configured.
Q14. What are the functions of a RIP message?
Used by a router, a routing information protocol is used through a router for requesting and receiving the
information of routing about the autonomous system. Routing information protocol message is a vector
routing protocol of distance. Also, RIP is known to be the oldest routing protocol based on distance-
vector, this uses the routing matric for employing the count of hops. Furthermore, loops of routing are
prevented by implementing the RIP message. Also, loops are avoided by imposing a number limit on the
hops allowed within a source and target. The routing information protocol uses the hop count which is
enhanced for the purpose of finding and calculating the distance of a network. In every 30 seconds, the
router which is running routing information protocol (RIP) transmits the information of routing table to its
routers available at the adjacent.
Q15.Why do OSPF messages propagate faster than RIP messages?
In the words of Warsame & Sevin (2019), Link state routing is the base for Open Shortest Path First
(OSPF), which is basically an intradomain routing protocol. An autonomous system acts as the domain
for the Open Shortest Path First protocol, also for the purpose of efficient and effective routing; the
autonomous system is further bifurcated into the area. The area comprises of hosts, network and routers,
through which only summarized and selected data is sent. Hence, this makes the OSPF message to be
very fast and precise as compared with the RIP messages which are dependent on the updates which are
received in every 30 seconds. Furthermore, when it comes to hop count number, RIP messages has only
15 hops in maximum while the OSPF messages have unlimited counts of hop with an improved load
balancing. This is the main reason for OSPF messages to travel quicker as compared to the RIP messages.
Q16. What is the purpose BGP?
The term BGP refers to the Border Gateway Protocol in which packets are managed and routed within
and across the internet along with the interchange of reachability and routing data between the routers at
the edge. Packets are controlled or handled by the Border Gateway Protocol between the networks and
autonomous systems directed by a single entity or an enterprise. For the best working of internet, BGP is
the most necessary protocol. Also for the task of controlling and managing the traffic along with the
internet, Border Gateway Protocol is needed. Another purpose of BGP is to maintain the paths which are
allotted to different gateway routers, networks, and hosts and find the best decision of routing on the basis

of that (Lima et al. 2019).
Q17. Compare and contrast distance vector routing method against link state routing method.
According to Geboers et al. (2019), there are various differences between the distance routing method and
link state method:-
 The entire table of routing is sent in the distance vector routing while only information of link
state is sent by the link state routing.
 Convergence is observed to be faster in link state routing method as compared with the distance
routing method.
 Distance vector is more exposed to the loops of routing in comparison with link state routing.
 The configuration is much simpler in distance vector as compared with link state.
 The topology of the entire network is known in the link state routing while it is absent in the case
of distance vector.
 IGRP and RIP are some of the examples of distance vector routing while the link state contains
the IS-IS and OSPF.

REFERENCES:-
Ranjit, D., French, J., & Swaminathan, N. (2019). U.S. Patent Application No. 15/685,237.
Pederzolli, F., Siracusa, D., Zanardi, A., Galimberti, G., La Fauci, D., & Martinelli, G. (2019). Path-
based fragmentation metric and RSA algorithms for elastic optical networks. IEEE/OSA Journal of
Optical Communications and Networking, 11(3), 15-25.
Boucadair, M., Sivakumar, S., Jacquenet, C., Vinapamula, S., & Wu, Q. (2019). A YANG Module for
Network Address Translation (NAT) and Network Prefix Translation (NPT) (No. RFC 8512).
Menon, A., Penfield, R., & Kaplan, H. S. (2019). U.S. Patent Application No. 10/257,061.
Yoakum, J. H., Singh, K., Ezell, J., & Johnston, A. B. (2015). U.S. Patent Application No.
14/141,798.
Liu, H., & Kawashima, M. (2019). Requirements for IPv6 Customer Edge Routers to Support IPv4-
as-a-Service.
Wijaya, C. (2011, December). Performance analysis of dynamic routing protocol EIGRP and OSPF
in IPv4 and IPv6 network. In 2011 First International Conference on Informatics and Computational
Intelligence (pp. 355-360). IEEE.
Onursal, O., & Sari, A. (2019). Enhanced Security for Network Communication With Proposed IS-IS
Protocol. In Applying Methods of Scientific Inquiry Into Intelligence, Security, and Counterterrorism
(pp. 269-290). IGI Global.
Warsame, M. A., & Sevin, A. (2019). Comparison and Analysis of Routing Protocols Using Riverbed
Modeler. Sakarya University Journal of Science, 23(1), 16-21.
Fiumano, M. F., Robertson, I. C. A., Hoskins, B. J., & Gaudutis, J. E. (2019). U.S. Patent Application
No. 16/107,907.
Lima, F. H., Vieira, L. F., Vieira, M. A., Vieira, A. B., & Nacif, J. A. M. (2019). Water ping: ICMP
for the internet of underwater things. Computer Networks, 152, 54-63.
Ghumman, F. A. Effects of IPV4/IPv6 Transition Methods in IoT (Internet of Things): A survey.
Yoakum, J. H., Singh, K., Ezell, J., & Johnston, A. B. (2019). U.S. Patent Application No.
16/144,709.
Abboud, A., Lahmadi, A., Rusinowitch, M., Couceiro, M., Bouhoula, A., Awainia, S. E. H., & Ayadi,
M. (2019). Minimizing Range Rules for Packet Filtering Using Double Mask Representation.
Araújo, J. D. T. (2019). U.S. Patent Application No. 16/025,182.

Geboers, M., Andelsman, V., Bainotti, L., Banal, M., Brans, E., Campagna, T., ... & Goswami, S.
(2019). Mapping Affect: exploring new protocols for visual analysis. Digital Methods Initiative
Winter School Wiki.