University Computer Networks Assignment: Protocols and Troubleshooting

This assignment delves into the core concepts of advanced computer networks. It begins with an exploration of the OSI model, detailing its seven layers and functionalities. The assignment then examines the benefits of VLANs, including enhanced security, simplified management, and improved user experience, along with the functionality of trunk ports. Furthermore, it identifies and explains five essential network troubleshooting tools, such as IP calculators and speed tests. The assignment also differentiates between public and private IP addresses, and discusses the concept of a universal crop's network. It then compares static and dynamic routing, and explores the differences between interior and exterior routing protocols. Finally, it explains the role of DHCP in assigning IP addresses and concludes with a definition of a router as a packet filter.

Running head: ADVANCE COMPUTER NETWORKS
ADVANCE COMPUTER NETWORKS
Name of the Student
Name of the University
Author Note

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SECTION A
TASK 1:
OSI model:
The term OSI stands for ‘Open systems Interconnection’ is a reference model that
describes how the communication happens between the existing applications over a network.
A reference model is basically a conceptual framework to understand about the relationships
(Xylomenos et al., 2014). The main purpose of this model is to provide guideline to the
developers as well as to the vendors, so the software programs and products that they created
for digital communication can interoperate and for facilitating a framework which is able to
describe about the functions of a telecommunication or networking system. In 1974 the OSI
model was developed by International Organization of Standardization (ISO) (Kreutz et al.,
2015).

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Fig 1: OSI model diagram
Layers: OSI model an architecture of 7 layers where each layer have different functionality
for performing. The layers are as follows:
1. Physical layer: It provides functional, procedural and electrical characteristics for
activating, deactivating and maintaining the physical links that send bit stream
transparently.
2. Data link layer: It provides procedural and functional means to the data transferring
and information between the entities of network. It also provides to activate, maintain
and deactivate the data link connection.
3. Network layer: It decides via which router/path the data should take. it transforms
outgoing messages to packets and combine the incoming messages for higher security
(Ensafi et al., 2014).
4. Transport layer: Depending on requirements of a network it can be so complex. This
layer does segmenting, multiplexing or splitting on data.
5. Session layer: It synchronizes and manages conversation between various application
6. Presentation layer: It performs data encryption, data compression and data
conversation.
7. Application layer: This layer provides directory services, mail services and network
resource.
SECTION B
TASK 2:
Benefits of creating VLANs: After proper implementation of VLANs, it can give benefits to
the business through stronger security, simplicity and experience improvement of the users

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(Nunes et al., 2014). One of the best things exist in VLANs is that VLANs simplifies the
management. By grouping the users logically into one virtual network makes it easy for
setting up as well as to control the policies of management at group level. The use of VLANs
also can help in improvement of security of a network by reducing external and internal
threats. Internally the separating users can improve privacy and security by ensuring that only
these users have right to access the network. The threats that are external are minimized too.
Use of VLANs provides easier fault management. Troubleshooting of the problems on a
network can be faster and simpler when several groups are isolated and segmented from each
other. VALNs can also help in improvement in the quality of services. It manages the traffic
of the network more efficiently for betterment in user experience. The users will be having
very few latency problems on their network as well as more reliability for the critical
applications. It makes the prioritizing traffic easier too.
Functionality of trunk port in VLANs: A trunk port is basically a port which is assigned for
carrying traffic for each VLANs accessible from a specific switch. An ethernet interface can
function either as an access port or a trunk port, but not the both at same time.
TASK 3:
The common conclusion comes at time of trouble shooting application, system issues
and odd PC is ‘It must be a network issue’. The 5 best tools for troubleshooting the networks
are as following.
1. Subnet and IP calculator: One of the most important tools for troubleshooting of a
network is the IP calculator. The Ip calculator is to be used for insuring an IP
selection that is correct along with this configuration of a correct IP address. But this
tool is mainly used by the network engineers of senior level. Most of the information

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have been obtained been obtained from the tools for calculating the more and longer
experience that someone have in the field.
2. Speedtest.net: This is so easy test which can be used for determining bandwidth of
the internet, which is available in a host that is specific as well as for determining the
connection quality of the internet. The measurement can be used also for
determining, whether the bandwidth amount that is offered by the connection, was
purchased from the provider of the internet. However, it is expected that the
difference in some amount of bandwidth (quoted and measured bandwidth) will
come.
3. Route: The route is used for displaying the current status of routing table under a
host. But this is vital in some situations like where multiple gateways as well as
multiple IP addresses available.
4. Putty / Tear term: At the time of connecting with a variety of several types of
networks, a SSH, serial client or telnet id required and both Tear and putty term
programs have the ability to provide those functionalities. To select one from these
two is a personal preference strictly (Kim & Feamster, 2013). In an effort for taking
the advantages of benefits from tracer and ping commands, the mtr and pathping
utilities were developed. Both of the tool take the information and functionality
which can be obtained from tool that are these types.
5. Ipconfig/ifconfig: In order to troubleshoot network related issues, identification of
the IP address is very important as it has an important role to play in the process of
network troubleshooting. In network troubleshooting, various hosts are affected
which requires IP address of those affected hosts for successful troubleshooting
(Clark, Sun, & Poovendran, 2013). Not every time the information about the IP is
known as this is the case when static IP is considered, when dynamic IP address is

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considered, the information is not available as the address of the host changes in
random fashion. Hence, proper utilities needs to be considered for executing this
troubleshooting process. These utilities include the utility of ipconfig on the windows
as well as the ipconfig utility on the machines that is based on Linux.
SECTION C
TASK 4:
Difference between public IP and private IP address:
Public IP: The IP address that is provided usually from the Internet Service Provider which
is connected via a router is known as public IP address. The main use of public IP is for
connecting PC along with other capable devices through a modem. In other word, it can be
said that public IP will be provided by ISP and after that it must be recognized by Internet
assigned Number Authority (IANA), after the recognition it will be able to connect the World
Wide Web to the connected modem (Wang et al., 2015).
Private IP: Public Ip is something that is exclusive or personal, it is meant simply that a
private network in someone’s own office or home can be structured from the Private IP
address. The network is actually assigned and recognized by the owner or user of the network
only. Also it can be provided by the owners’ router automatically.
Public IP address Private IP address
Connected via the provided Internet
network
Connected via LAN
Registered publicly with the network
information centre,
Not publicly registered.

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Assigned by ISP Assigned by router or User.
Universal crop’s network: The universal crops’ network is idea of one single network which
integrates existing voice as well as the telecommunication network that is public including
internet, data networks, cable TV and the video broadcasting networks (Johannisson, 2017).
At present each of them has different types of traffic as well as burden of the outdated
infrastructure are bearded by the older networks.
SECTION D
TASK 5:
Static and dynamic routing: The routers are designed for communication between each
other and for sharing information about the networks. The routers can be easily configured
for working with dynamic and static routers. Static routing means, a route that is manually
entered by the administrator of the network itself (Eizadi, Whittle & Wang 2015). The static
route is also known as non adaptive routing as this static route will be used always at the time
of sending data. As an example, it can be said that the administrator predetermines the data
path. It is so useful for the security of a network.
At present most of the routers are dynamic and also having the capability to be
configured statically.
The regular communication between the routers with the other routers is involved by
the dynamic routing technique. The routers are allowed to adapt and learn to an environment
that is changing. This is embodiment of switching packets with the routers adapting to
changes of network automatically as well as the system failure (Szajdecki, 2013).

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The dynamic routing technique will be more suitable for universal crop because at
present most of the routers are becoming dynamic in nature as well as they are having the
capability to be configured statically.
TASK6:
Interior and exterior routing protocol: The routing is a process to move data from one
network to other network. Though, routing is not necessary unless there have multiple
networks from different ranges of address. If there have combinations of different subnet
masks and IP addresses, then there have separated networks. If the user don’t have then the
user must need to perform switching and bridging. The routing protocols don’t need to be run
unless there have multiple networks have been served by more than one router as the static
routers that are manual are much easier for the networks that are small. There are two types
of routing protocols. One is the Interior routing protocols and another one is Exterior routing
protocols.
Interior Routing Protocols:
The routing is handled by the Interior Gateway Protocols (IGP) within an
Autonomous system such as one routing domain. The interior gateway protocol figures out
how to switch from one place to the other place within the owned routers (Vahlenkamp et al.,
2013). The protocols that are dynamic keep the track records of the paths that have been used
for moving data from end of one system to another insider network or even a set of networks
that are administrated ( all the networks that are managed combinedly, can be called as an
Autonomous System.
Exterior Routing Protocols:
For getting from one place to another place that is outside of a network, Exterior
Routing Protocols has been used. While using the internet, the Exterior Gateway Protocol

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must need be used (Panetto & Cecil, 2013). The routing that happens to the outside of an
Autonomous System is handled by the Exterior Gateway and also get the user from his own
network through the network of Internet service provider and into any of the other networks
(Sill, 2016). The companies are using BGP more than the Internet Service Provider for
allowing them for having load balancing and redundancy of the transported data from
internet.
Interior routing protocol is suitable for the universal crop as it handled within an
autonomous system.
SECTION E
TASK 7:
DHCP is standing for Dynamic Host Configuration Protocol. The IP addresses to
Computers and to the other devices on the each LAN (local area network) are assigned by the
DHCP built in server automatically. With the addition to IP address the default gateway
address, subnet mask, Domain name server and the other parameters of pertinent
configuration are also assigned by DHCP. The main reason behind DHCP is needed is for
simplifying to manage the IP addresses of a network (DeCusatis, (2013). More than one host
cannot be having the same IP address. Even if the user manually configures the IP address
then the will go to lead for giving errors.
TASK 8:
A router is basically a packet filter which is considered for classification of the packets based
on the filtering rules defined for the network (Xylomenos et al., 2014). It is basically a
network device that consists of the 3 network layers that allows it to filter packets. A typical
packet filtering router along with the defined rules permit some packets, whether some
packets are denied and this decision of whether to allow or deny some packets are based on

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IP addressed associated with the source and destination of the packet, source port and
destination port and the protocol that us associated with the packet. When such rules are
defined, access control lists or the ACLs are considered (Bora et al, 2014). This scenario is
based described with the example of a guard standing in front of the door and is asked to
allow people only based on the address proof they provide and if it matches with the specific
address provided. Now someone comes in front of the door and the guard asks to provide
address details and if it matches with list of the address provided to him, then only the guard
allows that person into the room. The same things happen here in case of the packet filtering
router (Alhamedi et al., 2014). When a particular packet is sent over the network, the router
after the packet arrives, extract information from the header of the packet and decides
whether to allow the packet or not through the router. The process of packet filtering is
executed at the network layer of the Open Systems Interconnection (OSI) model or the
Internet layer of TCP/IP (Zhang et al., 2014).
Conclusion:
Although the concept of computer and networking is not new, the applications that it is
powering is no doubt influential and these applications were not conceptualized earlier. The
advancement of digital networking is making possibility for advanced application for
enhancing the quality of the life through the technology and innovation. Although innovation
is taking place in the field of computer and network, technologies, protocol and standard that
were associated with the previous networking technologies are still considered and this is
where innovation and improvement is required in this context.

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