Advantages And Disadvantages Of Client-Server Network Model And LAN Comparison Essay.

A domain controller can be said to be a group of Sebastian’s sea creature’s employees account that are managed at a central point (Posey, 2012). This therefore means that the network model used at Sebastian Sea Creatures is Client-Server model. This model ensures that all the employees usernames and passwords are stored in a central point and can be accessed using any computer as long as the employee is connected to the network. With this model, even if one of the employee’s computer experiences any technical failure, the employee will be able to use another computer and log into his/her account using his/her normal credentials while waiting for the computer to be repaired. The Centralized Server in this model therefore, acts as a central storage point for all the employees account details, that is, usernames and passwords and Sebastian employees can be able to access it irrespective of what computer they use as long as they remember their log in account details (TechoPedia, 2017). 

This model enhances proper management of employees log in account details (Sparrow, 2011). With this model Sebastian Sea Creatures administration is able to monitor as well as control how employees access relevant information. With a dedicated server the administrator has a privilege of either activating or deactivating a given employee account details. This will allow proper use of the network resources by ensuring that employees access relevant information at any given time. The administrator is able to monitor every action performed by employees in the network. 

One main disadvantage of this model is that, if the server fails then the whole network breaks down (Sparrow, 2011). This is because the server is the backbone of the whole network and therefore Sebastian Sea Creatures employees relies on it in order to access their accounts and perform their tasks. Therefore, a failure on the server side means a failure of the whole Sebastian Sea Creature Network

It enhances proper management of information and users, resource accessibility and easy back up of stored information in the network.

Sebastian’s Sea Creatures has 25 workstations in their administration office.  You are the IT manager for the company and Sebastian has asked you to replace the 300Mbps wireless access point (AP) that services the office with a 100Mbps switch.  Will this increase or decrease the bandwidth available to each workstation?  Explain your reasoning by including estimates of effective bandwidth for each case.

Advantage of Client-Server Model

Replacing a 300Mbps wireless access point with 100Mbps switch will increase the network bandwidth for each workstation (Doctor, 2013). This is because each workstation of the 25 available workstations will be connected to a port in the switch and this means collision will be avoided since each port is dedicated to the connected workstation. Whereas, in the case of Wireless access point there are no dedicated ports that means, a possibility of a collision to occur is high and this does slow the network. With a switch in place, the 100Mbps is likely to be shared equally across all the active ports. For instance, having 25 workstations connected to a switch means that each workstation will have an approximate of 4Mbps while in the AP there is unevenly distribution of the 300Mbps thus reducing bandwidth for some of the workstations. A switch therefore, will improve the data transfer rate for each workstation and communication between the workstations in the network will be much fast.

Increased workstation bandwidth as a result of dedicated ports and approximately evenly distribution of network speed (Meraki, 2015). 

There are two other LANs at Sebastian’s Sea Creatures, one for the café (called CAFE) and one for the admissions gate (called GATE).  There are 5 workstations on each LAN.  On CAFE, the workstations connect to a 100Mbps hub.  On GATE, the workstations connect to a 100Mbs switch with all ports operating in half-duplex mode.  If you connected your laptop to GATE, would it be subject to more, the same or less collisions than if it was connected to CAFE?  You can assume data rates and traffic patterns are the same on each LAN.  Justify your answer by explaining the origin of the collisions.

The laptop will be subjected to less collisions as to when it would have been connected to CAFÉ LAN. This is because even though both the switch and hub are used to expand the network, their mode of operation is quite different (Diffen, 2013). A hub does not have any address table to determine where the communication comes from and where it goes. This therefore, means that, any information or message it receives, it forwards to all the devices connected to it and this might result to collision. A hub does not have any Collision Detection functionality and therefore it is unable to avoid collisions as well. On the other hand, a switch being an intelligent hub has a MAC address table and it is therefore able to determine the destination of a given information. In half duplex, a switch listens to the transmission media for any incoming message or action before it sends the message to the intended device using MAC address. This therefore, means less collision as it implements collision detection mechanism thus reducing the number of collision that might occur. 

Disadvantage of Client-Server Model

Collisions on a hub network are higher than when using a switch. A switch is more intelligent and it has CSMA/CD mechanism to detect collision across a transmission medium in a network.

A backbone medium should be more reliable since the whole network or the connection between intermediate Distribution Frame to Main Distribution Frame, solely depends on it. Even though UTP cable can be regarded to be faster in transmission speed, it is disadvantaged in some of its features that can make it unreliable in maintaining effective connection between the two end points. Some of these factors are:

UTP cable does not have the mechanism to shield it from being interfered with by electromagnetic signals which is electronic disturbance that could be caused by electricity waves during transmission (Lakhotia, 2010) especially when the UTP cable is closer to an electricity cable. The cable is therefore vulnerable to such interference and this could lead to loss of data or signal transmitted across the network connection. This therefore makes it not a suitable backbone transmission medium.

The fact that the UTP copper cables are not shielded means that, its signal could be disrupted by other signals in other transmission mediums (Hope, 2017). This leads to poor communication between the two connected points. Also crosstalk makes its transmission less secure since someone else connected to the network could tap what is being transmitted from the cable.   

With IPv6 the routing table is greatly reduced in size and this makes the routing process more of hierarchical nature hence all what the internet service providers does is to aggregate their client’s network prefixes into one prefix and communicate it to the IPv6 network. With this network, the breakdown of a message into packets is done on the source device but not in the router as it is the case with IPv4. This will improve networking communication as well as increase the transmission speed.

This enables packets with high bandwidth to be sent to multiple destinations at the same time across the network thus saving the whole network bandwidth that could be utilised if the network was only supporting unicast (Computing, 2011).  

Yes, it has. This version of IP improves the network speed and supports more network devices and information transfer (Discovery, 2016). 

Even though you know moving to IPv6 is a good thing, you realise that you can’t do it all immediately so will need to transition to it gradually.  Explain how it is that IPv4 and IPv6 could co-exist on the same networks at Sebastian’s Sea Creatures and describe two technologies that enable this. 

Week Two

This is where all the devices connected to the network are enabled to run both IPv4 and IPv6 simultaneously even though IPv6 is mostly preferred. Here all the switches, computers and routers use the two protocols to communicate across the network hence the name dual stack. This technology therefore promotes coexistence of both IPv4 and IPv6 in the same network. 

In this technology, one of the protocol is carried within the other protocol. That is, IPv6 can be encapsulated within IPv4. This means that packets with IPv6 can be forwarded to IPv4 network if IPv6 covers IPv4. Here, IPv6 carries IPv4 traffic across the network.  

The port address  of the MAC address table in the switch  changes as well taking the address of each device connected to specific ports.

This malware is referred to as Trojan horse. It hides itself on harmless applications that can be easily downloaded via the internet. This malware upon installation of the app, it collected information on Sebastian’s Sea Creature Systems and created security loopholes that interfered with the normal functionality of Sebastian’s applications thus leading to undesirable opening of gates between shark pool and swimming with dolphin’s tank causing a messy scenario.

To avoid such attacks from this malware, Sebastian Sea Creature organisation should ensure that their network and computers are well protected using anti malware software such as Kaspersky, Avast or any other quality antivirus software (AVG, 2017). 

This can be avoided by use of quality anti-malware software. The software detects and prevent against malware attacks.  

The most appropriate cloud computing type for this organisation is Infrastructure-as-a-Service commonly referred to IaaS. This is due to the fact that Sebastian Sea Creature company has a centralized server that could be a target for malicious attack. Therefore, in order to improve security, the server could be hosted on cloud which offers data storage and reliable virtual server. This will reduce the rate of attacks that could be targeted towards this organisation and also considering that organisations providing cloud computing services such as Azure are more secured.  

There are various types of cloud computing services which include IaaS, PaaS and SaaS. The provided hosting services across all aspects of information systems. 

This include use of encryption products such; safenet, which protect sensitive information coming out and coming in to the dedicated Sebastian Server. The data is transmitted across the network in an encrypted format thus making it hard for outsiders to access it.

This is where, each authorised person accessing Sebastian Server has a privilege of viewing a given set of information. This will mean that, only selected persons with given privileges will be able to access sensitive information. This access control mechanism will boost security of Sebastian Sea Creatures Information System. 

This can be achieved by use of:

1. Access Control Mechanism
2. Authentication Mechanism
3. Encryption of the transmitted data  

References

AVG, 2017. AVG. [Online]
Available at: https://www.avg.com/en/signal/what-is-a-trojan
[Accessed 19 September 2017].

Computing, N., 2011. Networking. [Online]
Available at: https://www.networkcomputing.com/networking/six-benefits-ipv6/1148014746
[Accessed 19 September 2017].

Daddy, S., 2013. Source Daddy. [Online]
Available at: https://sourcedaddy.com/networking/crosstalk.html
[Accessed 19 September 2017].

Diffen, 2013. Diffen. [Online]
Available at: https://www.diffen.com/difference/Hub_vs_Switch
[Accessed 19 Sseptember 2017].

Discovery, T., 2016. NEWS BLOG. [Online]
Available at: https://www.teamdiscovery.eu/advantages-ipv6-ipv4/
[Accessed 19 September 2017].

Doctor, T., 2013. Quora. [Online]
Available at: https://www.quora.com/What-is-the-difference-between-a-150mbps-and-300mbps-router
[Accessed 19 September 2017].

Hope, C., 2017. Cross Talk. Jargon, p. 1.

Lakhotia, G., 2010. Unshielded Twisted Pair Cables (UTP). Network Communication, p. 5.

Meraki, 2015. Cisco Meraki. [Online]
Available at: https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Wireless_Throughput_Calculations_and_Limitations
[Accessed 19 September 2017].

Posey, B., 2012. Part 5 – Domain Controllers. Networking Basics, pp. 1-13.

Sparrow, P., 2011. Advantages and Disadvantages. Client Server Network, 5 March.pp. 1-2.

TechoPedia, 2017. Techopedia. [Online]
Available at: https://www.techopedia.com/definition/4868/dedicated-server
[Accessed 19 September 2017].

Vaughan-Nichols, S. J., 2010. Five ways for IPv6 and IPv4 to peacefully co-exist. Networking, pp. 1-7.