Cyber Fundementals Block 4 -- Dolan Hall

Server

a computer on a network that manages resources with other systems on network

Client

computing device that connects with server to make use of resource

what is a thin client

it is a computer that relies heavily on another system to perform its operations, it has no hard drive

what is a thick client

a workstation computer functions independently of server and occasionally needs to connect to central server

what is a thick client known as

it is known as a rich or fat client

what workstation computer has many applications installed locally on the client hard drive

thick client

what is a workstation

a personal computer that may or may not be connected to a network and can function independently of a server

advantages of client-server model?

- central management of servers

- security and access rights

- management of resources

disadvantages of client-server model?

- expensive to setup and maintain

- increase workload, reduce network speed

- reliant on centralized server, failiure could lead to network collapse

what are two methods of network control?

workgroups and domains

Directory

How files are stored in a network

what is Active Directory

An advanced heirical directory used to manage user permissions and user access to network

Active Directory structure

two structures Logical, and Physical

what is Active directory server

A server that allows administrators to manage and store data from a network in a distributed database

What is a Logical structure

A grouping system of objects based on how they logically function

What are the three parts of AD logical structure

Configuration, Schema, Domain

What are the seven parts of Domain?

Tree, Forest, Forest Root, Child Domain, organizational Unit (OU), Object, Leaf

What do Configurations do?

It is the container that stores configuration objects for the entire forest

What does a schema consist of?

Objects, classes, attributes, and syntax

What is a schema?

Stores Classes and attribution definition for Active Directory objects

What does a schema define?

Defines rules that ensure objects are created and modified with consistency

What is a Domain

It is a group of users, servers, and resources sharing a database of account and security information.

what are domains commonly known as?

workgroup networks

What is the purpose of a Domain

Makes it easier to organize and manage resources, and security.

What are sites

Maps the physical structure of a network

Domain controller

manage domain security policy, authenticate user for access resources, search directory for info about users and network, enable user login

Global catalog server

Allows access to network resources in other domains within a tree or domain

Member servers

Used for dedicated network services such as, File and printer, application, database, and web servers

Domain client

a computer that has account in Active Directory

Who owns Active Directory

It is Propiotary to windows server OS

What does a DNS do?

resolves host names (websites) to IP addresses and vica versa

What are 3 components of DNS

Resolvers, Resource Records, Name Servers

What does Resolvers do?

Software that enables host to query a name server and resolve a host name into associated IP address

What are Resource Records?

It is an entry in a DNS database that contains information about domain names in DNS

What are Zones?

They are resource records contained in files

What do Zones represent?

A network, its location on internet, it's structure, Hosts or nodes in network

what is a name server?

provides namespace of all hosts on internet or network

What are the 3 types of name servers

Primary, secondary, caching only

What is Primary name server

contains master copy of zone files for the zone its has authority over, Authoritative meaning it can answer DNS queries for zone

Where does primary name server pass info to?

Secondary name server

Secondary name server

it receives zone files from primary, passes zone info to secondary or caching only server, it is Authoritative meaning can answer DNS queries from zone

Caching name server

It caches visited websites to avoid dns queries, not authoritative for any zone

What type of structure are DNS Name space?

it is a hierarchical inverted tree structure, tree is subdivided into zones

Forward lookup zone

Host name to IP address

Reverse lookup

IP address to host name

DNS synchronization

Primary Zone DB, Secondary zone DB

what is a zone transfer

copying the record of a zone file from a primary dns server to a secondary dns server

DNS structure

1) Root Domain => dot in google.com

2) Top level Domain (TLD) => com, edu, mil, org

3) Second level domain (SLD) => google, apple

4) Third level domain => www, mail, appleID

What is Root domain?

upper most layer of DNS namespace hierarchy

Top level domain (TLD)

under root domain, consists of name resolution for .com, .edu, .gov etc

Second level domain (SLD)

under TLD, popular websites like YouTube.com, Air Force.mil, Harvard.edu

Third level domain

It contains things like www from a link

What are authoratative domains

Second level and third level domains

How many servers was DNS originally created with

13 Servers

Fully Qualified Domain Name (FQDN)

The complete domain name for specific computer, or host, on the internet. Also known as Absolute Domain Name

How to map a FQDN (Fully qualified domain name)

https:// = Protocol

www = Third level

Google = Second level

com = Top level

(.) = Root

DNS Queries

A query lookup used to find DNS name resolution process

What is a Recursive Query

it is when a client provides the host name and the DNS resolver must provide an answer - record or error msgl. Each DNS server in hierarchy assumes responsibility

What is an Iterative Query

it is when a client provides the host name and the DNS resolver provides the best answer it can. Local DNS server will take responsibility

Non Recursive Query

Client provides host name and DNS already knows answer. No other queries are neccasary

What is a DHCP

It reduces configuration time for TCP/IP network, and automatically assigns IP address to client during logon process

What is a DHCP scope?

it is a range of IP addresses that lease out to DHCP clients

What are characteristics of DHCP scope?

- DHCP servers do not share scope information

- Set static IP addresses for servers or printers

- Scope must be unique

What are requirements for setting up Scope?

- Name of the scope

- Description of the scope (optional)

- Starting and ending IP addresses for use of Scope

- Subnet mask for the scope

- add Exclusions and Delays

- Lease duration

What are exclusions?

They are range of addresses that are not distributed by server

What are delays?

time duration by which the server will delay transmission of DHCP offer message

What is a DHCP lease?

Duration for which a DHCP server loans an IP address to DHCP client

what are the 4 steps for obtaining DHCP lease for IP address

Discover, Offer, Request, Acknowledge (DORA)

What is the DHCP lease default value?

Three days

What is the DHCP Process?

Discover, Offer, Request, Acknowledge (DORA)

what is DHCP Discover?

it is when the client broadcasts a request for a DHCP server

What is DHCP offer?

DHCP server on network offers an address to the client

What is DHCP Request?

The client broadcasts a request to lease an address from one of the DHCP servers

What is DHCP acknowledge?

The server acknowledges the client and assigns it any configured DHCP options

what is DHCP server?

A type of server that automatically assigns each computer an IP address from a list of available addresses

what are the two network models used with windows OS

peer-to-peer, client server

what does peer-to-peer do?

allows computers to communicate with every other computer

what are characteristics of peer-to-peer

No dedicated servers, no computer has more authority than another

what are work groups commonly known as?

peer-to-peer network

what are client servers

it is a network model used to communicate and share resources with clients on network

what is a proxy server?

a type of server that hides the addresses of all devices on the network from the internet

what is a virtual server

A software emulation of a physical server, allowing multiple isolated environments to run on a single physical server, sharing resources efficiently

what is a telnet server?

allows user to remotely log onto a host computer and execute tasks

what is a web server

a type of server used to store, process, and transfer web data using HTTP

What is a Virtual Machine?

It is a combination of software and OS that is tricked into thinking it has a dedicated hardware

What components of hardware does Virtual Machine have?

BIOS, hard disk, memory, CPU, and OS

What is a Host Server?

It is the physical computer hardware on which the virtual environment resides

What is a Hypervisor?

It is a link managing communication between host server and virtualized environment

What is another name for Hypervisor?

Virtual machine monitor (VMM)

What is a Type1 Hypervisor

virtualization software for creating virtual environments, installed directly on server hardware

advantages of type1 hypervisor

better performance, scalability, and stability

disadvantages of type1 hypervisor

limited hardware support due to built in server, confusing for admin because guest OS also serve as host OS

Where are type1 hypervisors used

data centers and central management implementations

what is another name for type1 hypervisor

bare metal hypervisor

How many OS can a Virtual Environment consist of

A Virtual Environment can consist of multiple OS

what is type2 Hypervisor known as

hosted hypervisor

What are advantages of Type2 hypervisor

better hardware compatibility, allow multiple OS, maintain application compatibility

what are disadvantages of Type2 hypervisor

increase memory and processor usage, degrade VM performance

where are Type2 hypervisors used

used on desktop because they allow running of multiple OS

What is a Type2 Hypervisor

virtualization software that runs on top of a host OS