midterms

Network Administration

aims to manage, monitor, maintain, secure, and service an organization’s network. However, the specific tasks and procedures may vary depending on the size and type of an organization.

Network administration

primarily consists of, but isn’t limited to, network monitoring, network management, and maintaining network quality and security.

Network monitoring

essential to monitor unusual traffic patterns, the health of the network infrastructure, and devices connected to the network.

Network monitoring

helps detect abnormal activity, network issues, or excessive bandwidth consumption early on and take preventative and remedial actions to uphold the network quality and security.

Network management

encompasses multiple administrative functions, including network planning, implementation, and configuration.

Network management

replanning the network based on changing organizational requirements

Network management

implementing the network for maximum efficiency

Network management

configuring various networking and security protocols

Network management

applying security patches and updating the firmware of the networking infrastructure, such as routers, hubs, switches, and firewalls

Network management

assessing the network for weaknesses

Network management

evaluating quality and capacity to increase or decrease network capacity and manage resource wastage

Network security

employs various techniques to ensure a network is secure

Network security

it uses multiple tools such as firewalls, intrusion detection or prevention systems, and anti-malware software to prevent or detect malicious activity in the network.

Network administration

aims to ensure a reliable, secure network conducive to business operations

Network administration goal

maintain a resilient, high-quality network

Network administration goal

plan and improve network capacity to enable seamless network access and operations

Network administration goal

leverage networking tools for network systems administration and better network administration control

Network administration goal

track and document relevant changes

Network administration goal

evaluate possible risks and orchestrate effective mitigations

Network administration goal

prevent activities compromising or using the network as an attack vector

Network administration goal

identify and mitigate intrusions to avoid security breaches

1. Fault Management

2. Configuration Management

3. Account Management

4. Performance Management

5. Security Management

Network administration key areas (5)

Fault management

Monitors the network infrastructure to identify and address issues potentially affecting the network. It uses standard protocols such as Simple Network Management Protocol (SNMP) to monitor network infrastructure.

Configuration management

Tracks configuration and related changes of network components, including switches, firewalls, hubs, and routers. As unplanned changes can affect the network drastically and potentially cause downtime, it’s essential to streamline, track, and manage configuration changes

Account management

Tracks network utilization to bill and estimate the usage of various departments of an organization. In smaller organizations, billing may be irrelevant. However, monitoring utilization helps spot specific trends and inefficiencies

Performance management

Focuses on maintaining service levels needed for efficient operations. It collects various metrics and analytical data to continually assess network performance, including response times, packet loss, and link utilization.

Security management

Aims to ensure only authorized activity and authenticated devices and users can access the network. It employs several disciplines such as threat management, intrusion detection, and firewall management. It also collects and analyzes relevant network information to detect and block malicious or suspicious activity.

Network Administration

installing, monitoring, troubleshooting, and upgrading network infrastructure, including both hardware and software components

Network Administration

monitoring network activity

Network Administration

implementing optimization techniques to improve network efficiency and utilization

Network Administration

managing and granting network access to users and endpoint devices

Network Administration (smaller organizations)

distributing software upgrades efficiently using tools such as Windows Server Update Services (WSUS)

Network Administration (smaller organizations)

planning and executing routine backups

Network Administration (smaller organizations)

managing and distributing licenses and maintaining compliance with licensing agreements

Network Administration (smaller organizations)

installing new software applications and hardware appliance

Network Administrator

responsible for managing and maintaining the network in real time

Network Administrator

focuses on the day-to-day aspects of managing and maintaining a network

Network Administrator

is responsible for managing and maintaining the network in real time

Network Administrator

ensures the network is secure by blocking suspicious activity and mitigating the risk of security breaches

Network Administrator

implements security programs based on hardware and software

Network Administrator

manages on-site networking servers responsible for business operations

Network Administrator

ensures network integrity and resilience to maintain service levels

Network Administrator

tests the network to uncover weaknesses and mitigate them

Network Administrator

monitors and tracks utilization

Network Administrator

applies utilization, authentication, and authorization policies to maintain the quality and security of the network

Network Engineer

designs network architecture and develops the entire network based on an organization’s requirements

Network Engineer

plans and implements both wired and wireless networks

Network Engineer

broadly manages the underlying network equipment

Network Engineer

strategically ensures network performance is as desired

Network Engineer

researches and introduces better technologies and implements them into the network lifecycle

Network Engineer

collaborates with network administrators to manage and remediate network issues

OSI

Open Systems Interconnection

OSI Model

It's a 7-layered framework for designing and implementing computer networks

OSI Model

provides a standardized way to understand and communicate how data is transmitted over a network

1. Physical (Layer 1)

2. Data Link (Layer 2)

3. Network (Layer 3)

4. Transport (Layer 4)

5. Session (Layer 5)

6. Presentation (Layer 6)

7. Application (Layer 7)

The 7 layers of the OSI model are:

Layer 1 – Physical Layer

The lowest layer of the OSI reference model

Layer 1 – Physical Layer

It is responsible for the actual physical connection between the devices

Layer 1 – Physical Layer

contains information in the form of bits

Layer 1 – Physical Layer

responsible for transmitting individual bits from one node to the next

Layer 1 – Physical Layer

When receiving data, this layer will get the signal received and convert it into 0s and 1s and send them to the Data Link layer, which will put the frame back together

Layer 1 – Physical Layer

Hub, Repeater, Modem, and Cables

1. Bit Synchronization

2. Bit Rate Control

3. Physical Control

4. Physical Topologies

5. Transmission Mode

Functions of the Physical Layer (5)

Bit Synchronization

The physical layer provides the synchronization of the bits by providing a clock. This clock controls both sender and receiver thus providing synchronization at the bit level

Bit Rate Control

The Physical layer also defines the transmission rate i.e. the number of bits sent per second

Physical Topologies

Physical layer specifies how the different, devices/nodes are arranged in a network i.e. bus topology, star topology, or mesh topology

Transmission Mode

Physical layer also defines how the data flows between the two connected devices. The various transmission modes possible are Simplex, half-duplex and full duplex

Layer 2 – Data Link Layer (DLL)

responsible for the node-to-node delivery of the message

Layer 2 – Data Link Layer (DLL)

main function of this layer is to make sure data transfer is error-free from one node to another, over the physical layer

Layer 2 – Data Link Layer (DLL)

When a packet arrives in a network, it is the responsibility of the____ to transmit it to the Host using its MAC address

Frame

Packet in the Data Link layer is referred to as ___

Layer 2 – Data Link Layer (DLL)

Switches and Bridges

• Logical Link Control (LLC)

• Media Access Control (MAC)

The Data Link Layer is divided into two sublayers:

Layer 2 – Data Link Layer (DLL)

The packet received from the Network layer is further divided into frames depending on the frame size of the NIC (Network Interface Card)

Layer 2 – Data Link Layer (DLL)

encapsulates Sender and Receiver’s MAC address in the header.

Layer 2 – Data Link Layer (DLL)

The Receiver’s MAC address is obtained by placing an ARP (Address Resolution Protocol) request onto the wire asking, “Who has that IP address?” and the destination host will reply with its MAC address.

1. Framing

2. Physical Addressing

3. Error Control

4. Flow Control

5. Access Control

Functions of the Data Link Layer (5)

Framing

a function of the data link layer. It provides a way for a sender to transmit a set of bits that are meaningful to the receiver. This can be accomplished by attaching special bit patterns to the beginning and end of the frame.

Physical Addressing

After creating frames, the Data link layer adds physical addresses (MAC addresses) of the sender and/or receiver in the header of each frame.

Error Control

The data link layer provides the mechanism of error control in which it detects and retransmits damaged or lost frames.

Flow Control

The data rate must be constant on both sides else the data may get corrupted thus, flow control coordinates the amount of data that can be sent before receiving an acknowledgment

Access Control

When a single communication channel is shared by multiple devices, the MAC sub-layer of the data link layer helps to determine which device has control over the channel at a given time

Layer 3 – Network Layer

works for the transmission of data from one host to the other located in different networks

Layer 3 – Network Layer

takes care of packet routing i.e. selection of the shortest path to transmit the packet, from the number of routes available

Layer 3 – Network Layer

The sender and receiver’s IP address are placed in the header by the _________

Packet

Segment in the Network layer is referred to as ______

Layer 3 – Network Layer

implemented by networking devices such as routers and switches

1. Routing

2. Logical Addressing

Functions of the Network Layer (2)

Routing

The network layer protocols determine which route is suitable from source to destination. This function of the network layer is known as routing.

Logical Addressing

To identify each device inter-network uniquely, the network layer defines an addressing scheme. The sender and receiver’s IP addresses are placed in the header by the network layer. Such an address distinguishes each device uniquely and universally

Layer 4 – Transport Layer

provides services to the application layer and takes services from the network layer

Segments

The data in the transport layer is referred to as ______

Layer 4 – Transport Layer

It is responsible for the end-to-end delivery of the complete message.

Layer 4 – Transport Layer

provides the acknowledgment of the successful data transmission and re-transmits the data if an error is found

Layer 4 – Transport Layer

Protocols used in ______ are TCP, UDP NetBIOS, PPTP.

Layer 4 – Transport Layer

At the Receiver’s side, ________ reads the port number from its header and forwards the Data which it has received to the respective application. It also performs sequencing and reassembling of the segmented data.

1. Segmentation and Reassembly

2. Service Point Addressing

Functions of the Transport Layer

Segmentation and Reassembly

This layer accepts the message from the (session) layer and breaks the message into smaller units. Each of the segments produced has a header associated with it. The transport layer at the destination station reassembles the message

Service Point Addressing

To deliver the message to the correct process, the transport layer header includes a type of address called service point address or port address.

• Services Provided by Transport Layer

• Connection-Oriented Service

• Connectionless Service

Thus, by specifying this address, the transport layer makes sure that the message is delivered to the correct process. (3)

Layer 5 – Session Layer

responsible for the establishment of connections, management of connections, terminations of sessions between two devices