Network and Security- Foundations- D315

Type 1 hypervisor

- Also referred to as a bare-metal hypervisor, bare-metal systems are ones that do not have an operating system already installed -Accessing details and managing your virtual machines is done through a remote system -Examples VMware esxi Microsoft hyper-v

Patch Panel

-A box designed as a junction point for twisted pair (TP) cable and fiber cable used in networks. -First step in organizing your cables

Firewall

-A security hardware appliance or software application that protects a computer or network from unwanted intrusion -Blocks unwanted connections from untrusted networks and can block basic network attacks

Modem {Physical and Data link Layer}

-Connects a LAN to an internet service provider -Converts digital signals into analog signals and vice versa

Wireless Access point {WAP}

-Extends a wired network to wireless connections -Involves the IEEE 802.11 group of standards that defines wireless LAN's {WLAN's} -Central connecting point for computers equipped with wireless network adapters - identifies each computer by its MAC address

Router{Network Layer}

-Interconnect two or more networks -Operate at the border of your network -Stores information about the systems that are connected to it and where to send requests when the destination is unknown -Works at the network layer of the OSI model

Switch {Data and Network Layer}

-Provides connectivity to devices in a local network -Creates a dedicated full-speed connection between two computers that are communicating with each other - makes use of the MAC address to deliver the message to the right destination

Type 2 hypervisor

-Sometimes referred to as a hosted hypervisor -Installed as an application on personal computer and laptop - Virtual machine shares the hardware resources with the hosted system -Examples Vmware workstation Virtual box

Network Interface Card (NIC) {Physical Layer}

-The interface on a computer or other device that connects to the LAN -Designed to take the communication off the physical cable or wireless signal and present it to the computer for processing -Each NIC has a unique physical address known as a MAC address

Hub {Physical Layer}

-The simplest device used on an Ethernet network for connecting devices to each other -split the bandwidth of a connection among all the computers connected to it - do not perform any packet filtering or addressing functions but instead broadcast data to all computers connected to it

Wireless Local Area Network (WLAN)

A LAN with all devices connected wirelessly Users and devices can be placed anywhere and moved anywhere in the coverage area Easy and inexpensive to install

Multi-Cloud

A cloud deployment model where the cloud consumer uses multiple public cloud services.

Hybrid Topology

A combination of different topologies Inherits the advantages and disadvantages of each combined topology Offers the benefits of flexibility very effective and sealable but can be costly

Gray hat hackers

A cross between black and white—they will often illegally break into systems merely to flaunt their expertise to the administrator of the system they penetrated or to attempt to sell their services in repairing security breaches.

Purple Team

A mode of penetration testing where red and blue teams share information and collaborate throughout the engagement.

Advanced Persistent Threat (APT)

A network attack in which an intruder gains access to a network and stays there undetected with the intention of stealing data over a long period of time.

Storage Area Network (SAN)

A network that allows access to storage devices instead of general network purposes SANs are dedicated to storage devices and the servers that need access to them Allows servers to access tape libraries and disk array like they are locally attacked devices

Personal Area Network (PAN)

A network that is created to center around a person and their devices Communication over connections such as bluetooth or USB

Weak Password

A password that is short in length (less than 15 characters),uses a common word (princess), a predictable sequence of characters (abc123), or personal information (Braden).

Coaxial cable

A single copper wire surrounded by layers of plastic insulation and sheathing is used mainly in cable television and cable Internet service.

Vulnerability Tester

A vulnerability tester is responsible for scanning servers and network devices for known vulnerabilities

Tree Topology

Acts as both a star and bus topology The network is divided into multiple levels or layers The top device is known as a root node A parent-child hierarchy between nodes

ARP

Address Resolution Protocol Displays the MAC address mapping for the hosts that have been discovered in the ARP cache

Bus Topology

All the devices are connected to a shared single cable Bus topologies are uncommon today Computers in a bus topology physically tap into the network cable using special adapters The ends of the cables have terminators In a bus topology only one computer can communicate at a time All traffic transmitted is received by everyone

Star Topology

Also known as a hub-and-spoke network Composed of a central network device, such as a switch or a hub Each device is individually connected to the central network device Star topologies are the most common type found in LANs

Repeater{Physical Layer}

Amplifies that signal it receives so that it can travel a longer distance

Decentralization

An approach that puts the computer power in the user's devices rather than a data center

script kiddie

An attacker with little expertise or sophistication. Script kiddies use existing scripts to launch attacks.

Cat 6a cable

An improvement of the cable Cat 6 standard, supporting the same standard and lengths, {with the ability to run 10 Gbps over 100 meters maximum}, but using a higher quality cable that is more resistant to interference. This is most commonly used in wired networks today

telnet/ssh

Both used to manage accounts and devices remotely SSH is encrypted Telnet is unencrypted

fiber-optic cable

Cable that uses light guided through thin glass tubes instead of electrical signals to transmit data. It is very fast, but also expensive.

Misconfigured firewall

Can allow traffic that should be blocked and reduce the overall security of the network. It is a good policy to regularly review your firewall configuration identify what each rule does, remove only rules that are no longer needed, and regularly change the password

Bridge {Data link Layer}

Connects two or more networks Forwards data to next network with analysis Not widely used in modern networks

Cloud Computing

Consider the meaning and business implications of some of the more well-known and accepted characteristics of cloud computing: on-demand, self-service, resource pooling, elastic, accessible, and measurable.

Local Area Network (LAN)

Consist of computers connected within a limited area, such as a house, lab, or office building LAN's use Ethernet, wi-fi, or a combination of both.

Wide Area Network (WAN)

Covers a large geographical area within its network WAN networks can span cities, countries, or the entire globe The internet is an example of WAN

Virualization

Creates multiple "virtual" machines on a single computing device Virtual devices operate similarly to their physical counterparts. Benefits of virtualization: -Deploy new virtual device quickly -It is easier to move virtual devices within a data center or between data centers. -Can increase or decrease resources allocated based on it's utilization rising and falling

TCP Dump

Displays TCP/IP packets and other network packets that are being transmitted over the network Used a packet sniffer Displays in readable format for troubleshooting Not native to either Linux and window

Finger

Displays information about a user or users on a remote system Includes last log-in and username Primarily used in linux

netstat

Displays information about active ports and their state Useful for troubleshooting

nslookup

Displays information for display DNS information Used for troubleshooting DNS problems Displays names to ip address mappings Primarily used in windows

Cat 5e cable

Doubles the number of twisted pairs to four for up to 1 Gbps {gigabits per second} over up to 100 meters

FTP

File Transfer Protocol Copies files from one host to another host Data is unencrypted; for encryption, use FTPS, which utilizes SSL/TLS} Uses TCP for reliability Used often on WAN's and the internet

Hybrid Cloud

For hybrid cloud computing, the customer will require a dedicated connection between their on-premises data center and the public cloud provider. this connection may be a virtual private network {VPN} established over the internet or a dedicated wide area network {WAN} connection maintained by a telecommunications provider

Mesh Topology

Full mesh: every mode of connection to all other nodes Partial mesh: each node connects to a few other nodes Typically used for requirements of high availability and redundancy The most expensive and most complex topology

Single-mode fiber

Have several thin glass strands { in rare cases, plastic} covered protective insulation. Single-mode cables have thin 10-micron strands and support a narrow range of wavelengths and higher bandwidth, making them ideal for submarine cabling across continents

Nation states

Have substantially larger budgets to hire hackers then the average criminal enterprise

Peer-to-Peer Model

In a peer-to-peer network, client computers act as both servers and workstations because they share files and printers while allowing a user to log on and use the client computer for normal tasks

Transport layer (layer 4)

In this layer protocols ensure that data are transferred from point A to point B reliably and without errors. this layer services include flow control, acknowledgment, error correction, segmentation, reassembly, and sequencing.

IaaS (Infrastructure as a Service)

Infrastructure refers to the physical layers {servers}, storage, and networking that are required to exist before you can create any virtual servers or install any application

Personal Devices within the Network

Many businesses are adopting a mobile computing strategy that often includes a concept known as bring your own device, {BYOD}, which encourages users to bring their personal computers, tablets, or phones to work to use on the network

Black-hat hackers

May or may not be IT professionals but possess the knowledge and will to breach system for profit

Multi-mode fiber

Much cheaper than single-mode across shorter distances. The fiber in these cables is thicker, from 50 to 100 microns. Because of their thickness, they can run a wider frequency of light over shorter distances, from a couple of thousand meters to a couple of miles.

White hats hackers

Non-malicious hackers who attempt to break into a company's systems at their request

OSI Model

Open Systems Interconnection Model

Default password

Passwords on system administration, user, or service accounts predefined in a system, application, or device; usually associated with the default account. Default accounts and passwords are published, well known, and therefore easily guessed.

Metropolitan Area Network (MAN)

Provides networking across a larger area, such as a whole city Made up as many organizations within a city

Campus Area Network (CAN)

Provides networking of multiple LAN's across a limited area Each single building would typically have its own LAN Typically, connects LANs owned by a single company, university, government agency, etc

ipconfig

Provides the user with the IP, subnet mask, and default gateway for each network adapter With/all can display MAC address, DHCP status and lease information Used in windows

Nmap{network mapper}

Scans networks for hosts and open ports Used to determine what is deployed on a network Not native to either linux or windows

SCP

Secure Copy Protection Used to copy files between servers Uses SSH for authentication and encryption

ifconfig

Similar to ipconfig Used to configure the network interface Used in linux

tracepath command

Similar to traceroute/tracert Display the path taken by packet to its destination Used in linux { any user can use}

SaaS (Software as a Service)

Software as a service allows consumers to store and potentially publish information without the need to manage the underlying application or infrastructure

Hypervisor

Software that creates and manages virtual machines on a server or on a local computer Also called a virtual machine manager (VMM).

Insider threats

Some of the most potent threats come from people within your organization. Because they have legitimate access to systems, they are in a position to hack from the inside of the network, often undetected.

CAT 4 Cable

Supports 16 Mbps for up to 100 meters and is not commonly used today

Cat 3 cable

Supports up to 10 Mbps {megabits per second} for up to 100 meters and is commonly used for phone lines today

Blue Team

The blue team defends

PaaS (Platform as a Service)

The cloud provider is responsible for the virtual servers and, in some cases, the services that run on top of them, such as database engines, and provides you with a platform on which you can run your code or store your data

Ring Topology

The computers are connected to form a closed loop The computers are connected in a single line Each computer on the ring has an input port and an output port More reliable than a bus topology but communication still falls if the ring is broken A dual-ring topology provides high availability

industrial espionage

The process of gathering corporate information illegally or unethically.

Red Team

The red team attempt to compromise the security

Zero-Day

The term zero-day alludes to the fact that the exploit or vulnerability is not yet known by the public, meaning there is no patch available to mitigate this vulnerability

Public Cloud

There are many public cloud providers, but some providers, such as Amazon Web Services {AWS}, Microsoft Azure, and Google Cloud Platform {GCP}, are more well-known because of their marketing and experience in the industry.

Community cloud

These clouds are data centers that are jointly owned and operated by the tenants

client/server model

This approach offloads some of the computing requirements from the data center's servers, but more importantly, the client-server model allows application designers to implement advanced user interfaces that would not otherwise be possible in a web-based or terminal-based application.

Network Layer

This layer defines the logical transmission protocols for the whole network. The main protocols that live in this layer are internet protocol (IP), internet control message protocol (ICMP), and address resolution protocol (ARP).

Network interface Layer

This layer establishes how data should be physically sent through the network.

Session Layer (Layer 5)

This layer is responsible for connection establishment, session maintenance, and authentication.

Application Layer (Layer 7)

This layer is responsible for network applications (like HTTP or FTP) and their production of data to be transferred over the network.

Application Layer

This layer is responsible for the communication protocols between nodes. The protocols in this layer include hypertext transfer protocol (HTTP and HTTPS), Secure Shell (SSH), and network time protocol (NTP), among many others.

Transport Layer

This layer is responsible for the end-to-end transport of data. The protocols that live in this layer are transmission control protocol (TCP) and user datagram protocol (UDP).

Data Link Layer (Layer 2)

This layer is responsible for the error-free delivery of data to the receiving device or node. This layer is implemented through the use of devices such as switches and bridge devices, as well as anything with a network interface, like wireless or wired network cards.

Physical Layer (Layer 1)

This layer is responsible for the physical connections of the devices in the network. This layer is implemented through the use of devices such as hubs, repeaters, modem devices, and physical cabling.

Network Layer (Layer 3)

This layer is responsible for the transmission of data between hosts in different networks as well as routing of data packets. This layer is implemented through the use of devices such as routers and some switches.

Presentation Layer (Layer 6)

This layer is responsible for translating data from the application layer into the format required to transmit the data over the network as well as encrypting the data for security if encryption is used.

Ping command

Tools for testing connectivity to other hosts Sends internet control message protocol {ICMP} to a host and listens for the reply Replies displays time it took and time to live {TTL}

Traceroute/Tracert command

Trace the route an IP packet takes to it's destination Display each hop {next router} with its IP address and the time it takes to receive the packet Traceroute is linux command { can only be used by super user} Tracert is windows command

TFTP (Trivial File Transfer Protocol)

Transfers a file from a client to a server or from server to a client Uses UDP Used on reliable {local} network

TCP/IP

Transmission Control Protocol/Internet Protocol

unsheilded twisted pair (UTP)

Unshielded twisted pair cables are created when pairs of wires are tested around each other to protect and cancel out interference from each other and outside sources.

Cat 6 cable

Used in Ethernet LAN's and data centers, cat 6 is made up of four woven twisted pairs {more twisted per linear foot} and supports 1 Gbps for up to 100 meters or 10 Gbps for up to 55 meters

CAT-5 Cable

Used in Ethernet LAN's containing two twisted pairs, allowing for up to 100 Mbps up to 100 meters between the devices and the switch, hub, or router. This has been practically replaced by the cat 5e specification

Route

Used to display the current route tables on a host Can be used to add or remove routes

Who is

Used to lookup who owns a domain or block of IP address Includes: name, email address, and physical address Can purchase privacy to hide this information Primarily used on linux

Dig

Used to query the DNS name servers Helpful in troubleshooting DNS problems Replaced nslookup in linux OS

Centralization

Users logged on to machines called dumb terminals to perform their task. They were so named because the terminal had no intelligence or sophistication.

White Team

White team that observes the festivities and may even serve as referee

Private Cloud

a cloud that is owned and operated by an organization for its own benefit