Networking Fundamentals
Answer 1
Open System Interconnection (OSI) model
It is a framework for networking which basically execute the protocols in specified layers and perform the communication from one layer to the other. Majorly it is categorized in the 7 logical progressions layers.
Physical Layer
This is the lowest layer of open OSI model. This layer is responsible for maintaining the physical connection between various network devices. The data which is travel in this layer is in the form of bits as shown below. Various functions performed by the physical layer are bit synchronization, bit rate control, physical topologies, and transmission mode. There are various devices used in this layer such as Hub, repeater, cables.
Data Link Layer
This layer used for acquiring the data from the previous layer that is a physical layer. The main purpose of the Data Link layer to monitors the data bites as well as physical errors transmission into the data called “Frames”. It also supervises the addressing associated schemas that are networks of Ethernet, common physical medium which controls the access of different devices. Moreover, the Data link layer is one of the complex layers as compared to other OSI model layers. It is subdivided into two major parts that are “Logical Link Control” and “Media Access Control”. It includes various technologies such as NIC (Network Interface Card), Bridges. In this layer data is travel in the form of frames. There are various functions performed by layer are Framing, physical addressing, error control, flow control, access control, etc.
Network Layer
In this layer transmission of data take place from one node to another node over the network (Costa, 1998). This layer takes care of the packet routing in order to select the shortest path for transmitting the packet from a number of routes. The network technology associated with this layer such as Token ring, Ethernet, Relay frame, etc. EIGRP, DDP, and ICMP. In this data is travel in form of Packet.
Transport Layer
The motive of this layer is to provide end-to-end connectivity in the network. This layer provides a logical transmission of data between application processes running in different nodes. In this layer, data is in Segment form and along with this the main motive of this provides the acknowledgment for successful transmission of data and if there is an error in data it re-transmits the data. There is a various function performed by this layer such as Flow & Error control, segmentation and various services provided by this layer are connection-oriented services and connectionless services.
- Session Layer
This layer is basically accountable for building the connection, maintenance and checks the security, authentication. Session layer also responsible for handling the techniques for supervising the sessions. It provides various functions such as: – During a session, acknowledgment of data receiving, dialog controller, Synchronization of data flow, etc.
- Presentation Layer
Presentation layer also named as a Translation layer. The layer extracts the data from the application layer and manipulates as per required format in order to transmit it over the network. There are various functions of this layer such as Encryption/Decryption, Graphics formatting, Compression, etc.
- Application Layer
This is the topmost layer of the OSI model. The main purpose of this layer is to provide an abstraction technique that specifies the shared communication protocols and interface technique used by the node in a communication network. This layer also provides a window for the various application services in order to access the network such as Skype Messenger, browser, etc. This layer is also known as Desktop layer.
Software Layer and Hardware layer Differentiate
Software layer: – Software Layer layer is responsible for providing software access for various network services with the use of end devices such as a smartphone, PC, laptop, etc. The OSI model layer working in this layer are network layer, Physical layer, transport layer, data link layer.
Hardware layer: – Hardware layer is responsible for maintaining the physical connection between different network devices. In these various hardware network devices and cables are used such as Coaxial cables, RJ45 cable, Hub, repeater, etc. Hardware layer includes three layers of OSI model that are Application layer, Session layer, Presentation layer.
The position of Internet layer of TCP/IP is between the network layer access layer and transport layer. In this layer data packets known as IP, datagrams contain the destination and source address details which are used to forward the datagrams between various nodes over the network. Moreover, this layer is also responsible for routing IP datagrams packets. There is a various protocol which is working under this layer are ICMP, IP, ARP, RARP, IGMP, etc. This layer defines the protocols which are responsible for logical transmission of data over the network.
Answer 2
Hands-on-Project 2-3
The first step is to input the web address that is www.gestioip.net/cgi-bin/subnet_calculator.cgi in the Web browser URL filed.
Now, enter the IP address as 192.168.0.0 in the “IP address” field and along with this user has to select “BM” as 24 (255.255.255.0-254 hosts) and click on “Calculate” button as shown below. In the screenshot below, we can see the details regarding the IP address class, netmask address, mapped Ipv4 address, etc.
Hands-on-project 3.2.
Firstly open Wireshark application as shown below.
After that, we have to select Capture and then go to options and tick on the Wi-Fi interface.
Now, Run CMD with Administrator permission and after that in order to check the IPv6 IP address of system enter “ipconfig” command.
Now, we have to have to ping the local IPv6 IP address as shown below and enter the “exit” command to close the terminal.
Now, go to capture and stop the capturing of packets.
Now, enter ipv6 or icmpv6 or dhcpv6 in filter toolbar.
Noe, click on IPv6 packet and from packet details pane notice the IPv6 version details.
Now, we have to check traffic flow details, Payload Length, Next Header, Hop Limit from packet details pane as shown below.
After that, we have to save the file using “ch03_IPv6fields” as shown below.
Answer 3
IP:- It stands for Internet protocol which is used over the network in order to transfer data from one device to another device. All the network devices connected with the network are assigned with a unique IP address so that all the devices should be uniquely identified.
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MAC: – It stands for Media Access control address. MAC address is the system address which is linked with every system of the network. It is not changeable with respect to time. The main purpose of MAC is to provide unique hardware address to every node on a local area network.
MAC address and IP address are two main things which are used over the network. All the devices in the network have a unique IP address and MAC address. This MAC and IP address are used for unique identification of devices in the network. Whenever one device sent data to another device in the network, Address Resolution Protocol (ARP) check the target host entry in his ARP table. In ARP table there are various entries of the physical address of the machine which are linked with a unique IP address.
Importance of ARP Protocol
ARP protocol is a protocol which is used for mapping of IP address with the MAC address or physical address which is recognized in the Local network. ARP cache table is used to maintain a correlation between the MAC address which is linked with a corresponding IP address. For example: when a source machine sends information to another machine over the network then gateway device ask ARP protocol in order to find out the target machine (Samvedi, Owlak & Chaurasia, 2014). After that, ARP protocol check in his ARP cache table and if ARP found the destination address in his table then it directly send data to that device otherwise ARP protocol sends an ARP broadcast request packet in a special format to every machine of the network and machine that recognizes the IP address send ARP reply message so that ARP update the entry in his ARP cache table and after that packet is directly sent to the target device.
Answer 4
In this part, we have to create a network IP addressing plane for the Foreshore IT solutions organizations. It is a large organization which has several different departments. The organization has six sites across Brisbane which have different departments. In this, we have to make the IP address plane for the organization for HQ, BR1, and BR2.
A total number of Host requirements in each site are given below:
Site
Department
Number of Hosts
HQ
Sales
16000
Marketing
8000
BR1
Advertising
2000
Online Sales
4000
BR2
Product Support
1000
Technical Support
500
The network address that is provided for use isè 180.XY.0.0/16 (XY is last two students of student_ID).
Therefore, the IP address becomes 180.25.0.0/16.
Network Design
Network Design created for Organization is shown below.
Network IP Addressing Scheme
In the table below, we can see the current IP addressing Plan which is designed for the Organization with the use of VLSM subnetting technique.
Name of department
The required number of hosts
IP address assigned
Network Address
CIDR
Subnet Mask
IP Address Assignable Range
IP Broadcast Address
Sales
16000
16382
180.25.0.0
/18
255.255.192.0
180.25.0.1 – 180.25.63.254
180.25.63.255
Marketing
8000
8190
180.25.64.0
/19
255.255.224.0
180.25.64.1 – 180.25.95.254
180.25.95.255
Online Sales
4000
4094
180.25.96.0
/20
255.255.240.0
180.25.96.1 – 180.25.111.254
180.25.111.255
Advertising
2000
2046
180.25.112.0
/21
255.255.248.0
180.25.112.1 – 180.25.119.254
180.25.119.255
Product Support
1000
1022
180.25.120.0
/22
255.255.252.0
180.25.120.1 – 180.25.123.254
180.25.123.255
Technical Support
500
510
180.25.124.0
/23
255.255.254.0
180.25.124.1 – 180.25.125.254
180.25.125.255
IP Address assigned in different LAN/WAN interfaces
The table below describes the LAN/WAN interface IP Addresses.
Name of Site
Interface
IP Address Assigned
HQ
S0/0/1
162.10.10.1/30
S0/0/0
162.10.10.6/30
G0/1
180.25.64.1/19
G0/0
180.25.0.1/18
BR1
S0/0/1
162.10.10.4/30
S0/0/0
162.10.10.5/30
G0/1
180.25.96.1/20
G0/0
180.25.112.1/21
BR2
S0/0/1
162.10.10.2/30
S0/0/0
162.10.10.3/30
G0/1
180.25.120.1/22
G0/0
180.25.124.1/23
New Network IP Addressing Scheme After Increase of 40%
The organization expected that there is an increase in employees’ rate with 40%. The new IP addressing plan and number of IP address required new scheme is discussed below.
Site/Department
Current IP Address
IP Address with an increase of 40%
Total Number of IP Address after a 40% increase
HR
Sales
16000
6400
22400
Marketing
8000
3200
11200
BR1
Advertising
2000
1600
2800
Online Sales
4000
800
5600
BR2
Product Support
1000
400
1400
Technical Support
500
200
700
The IP addressing plan which is created with the use of VLSM subnetting technique is shown below.
Name of Subnet
IP Address required
IP Address assigned
Network Address
CIDR
Subnet Mask
IP Address Assignable Range
IP Broadcast Address
Sales
22400
32766
180.25.0.0
/17
255.255.128.0
180.25.0.1 – 180.25.127.254
180.25.127.255
Marketing
11200
16382
180.25.128.0
/18
255.255.192.0
180.25.128.1 – 180.25.191.254
180.25.191.255
Online Sales
5600
8190
180.25.192.0
/19
255.255.224.0
180.25.192.1 – 180.25.223.254
180.25.223.255
Advertising
2800
4094
180.25.224.0
/20
255.255.240.0
180.25.224.1 – 180.25.239.254
180.25.239.255
Product Support
1400
2046
180.25.240.0
/21
255.255.248.0
180.25.240.1 – 180.25.247.254
180.25.247.255
Technical Support
700
1022
180.25.248.0
/22
255.255.252.0
180.25.248.1 – 180.25.251.254
180.25.251.255
Calculations
The calculations which are done for the above IP addressing plan are discussed below. These calculations are done with the help of VLSM technique.
Sales
Before Increase
After a 40% Increase
IP Address needed
16382
32766
Host Allocated
2hostbits-2
= 214-2
è 16382
2hostbits-2
= 215-2
è 32766
Network Address
180.25.0.0
180.25.0.0
CIDR/Subnet Mask
/18(255.255.192.0)
/17 (255.255.128.0)
Marketing
Before Increase
After a 40% Increase
IP Address needed
8190
16382
Host Allocated
2hostbits-2
= 213-2
è 8190
2hostbits-2
= 214-2
è 16382
Network Address
180.25.64.0
180.25.128.0
CIDR/Subnet Mask
/19(255.255.224.0)
/18(255.255.192.0)
Online Sales
Before Increase
After a 40% Increase
IP Address needed
4094
8190
Host Allocated
2hostbits-2
= 212-2
è 4094
2hostbits-2
= 213-2
è 8190
Network Address
180.25.96.0
180.25.192.0
CIDR/Subnet Mask
/20(255.255.240.0)
/19(255.255.224.0)
Advertising
Before Increase
After a 40% Increase
IP Address needed
2046
4094
Host Allocated
2hostbits-2
= 211-2
è 2046
2hostbits-2
= 212-2
è 4094
Network Address
180.25.112.0
180.25.224.0
CIDR/Subnet Mask
/21(255.255.248.0)
/20(255.255.240.0)
Product Support
Before Increase
After a 40% Increase
IP Address needed
1022
2046
Host Allocated
2hostbits-2
= 210-2
è 1022
2hostbits-2
= 211-2
è 2046
Network Address
180.25.120.0
180.25.240.0
CIDR/Subnet Mask
/22(255.255.252.0)
/21(255.255.248.0)
Technical Support
Before Increase
After a 40% Increase
IP Address needed
510
1022
Host Allocated
2hostbits-2
= 29-2
è 510
2hostbits-2
= 210-2
è 1022
Network Address
180.25.124.0
180.25.248.0
CIDR/Subnet Mask
/23(255.255.254.0)
/22(255.255.252.0)
In the future organization can implement “dual stack network” technique in which the organization has to install dual stack supported devices. The implementation of dual stack technique will provide organization to IPv6 network with IPv4 network. This will resolve the increase of hosts addresses in the organization in the future.
References
Costa, L. (1998). Open Systems Interconnect (OSI) Model. Sagepub. Retrieved from https://journals.sagepub.com/doi/full/10.1177/221106829800300108
Samvedi, A., Owlak, S., & Chaurasia, V. (2014). Improved Secure Address Resolution Protocol. Computer Science & Information Technology ( CS & IT ). Retrieved from https://www.researchgate.net/publication/263048849_Improved_Secure_Address_Resolution_Protocol