Question

•What is a port?

•What is Apache? Modules and Directives? The first application we really looked at in the VM world

What is Vagrant and what is the relationship to VirtualBox?

•What is the relationship between your virtual machine and your local machine?

What vagrant provides and what virtual box provides?

If there is no virtualbox will Vagrant work? Vice versa

•Describe the difference between the messaging formats and why we might choose one over the other

•What role did tshark play in examining TCP and UDP messages?

•What did netcat provide? Describe your answer

Apache

•What is a symbolic link and why do we care about them with respect to Apache?

•If you were modifying Apache to run SSL (https), this generally requires that port 443 is open. While you can certainly set up things on the virtual machine to function at port 443, what else would have have to do to observe SSL working on our local machine? (Hint: think port forwarding).

•When deploying a module like Dav or Apache, describe the relationship between symbolic linking, modules, and configuration files.

Subnets

•How would you use the broadcast IP to send a message to all computers in the subnet?

•Describe two reasons why an administrator would want to manage the size of subnets.

•provide 3 sentence

•netcat - relationship with ports

•ping & route - relationship with subnets

•ifconfig - describe what you see // reconfigure

•ls, pwd, cd, mv, nano, ssh, ln, sudo, mkdir, cd

Answer 1

What is a port?

---> On computer and telecommunication devices, a port (noun) is generally a specific place for being physically connected to some other device, usually with a socket and plug of some kind.

---> Typically, a personal computer is provided with one or more serial ports and usually one parallel port.

---> The serial port supports sequential, one bit-at-a-time transmission to peripheral devices such as scanners and the parallel port supports multiple-bit-at-a-time transmission to devices such as printers.

---> In programming, a port (noun) is a "logical connection place" and specifically, using the Internet's protocol, TCP/IP, the way a client program specifies a particular server program on a computer in a network.

What is Apache? Modules and Directives? The first application we really looked at in the VM world

What is Vagrant and what is the relationship to VirtualBox?

---> Apache is the most widely used web server software.

---> Developed and maintained by Apache Software Foundation, Apache is an open source software available for free.

---> Apache HTTP Server is a free and open-source web server that delivers web content through the internet.

---> It is commonly referred to as Apache and after development, it quickly became the most popular HTTP client on the web.

---> Apache is just one component that is needed in a web application stack to deliver web content. One of the most common web application stacks involves LAMP, or Linux, Apache, MySQL, and PHP.

---> It is a modular, process-based web server application that creates a new thread with each simultaneous connection.

---> It supports a number of features; many of them are compiled as separate modules and extend its core functionality, and can provide everything from server side programming language support to authentication mechanism.

Three directives available in apache config file that is,

TransferLog: Creating a log file.

LogFormat : Specifying a custom format.

CustomLog : Creating and formatting a log file.

---> VirtualBox is basically inception for your computer. You can use VirtualBox to run entire sandboxed operating systems within your own computer.

---> Vagrant is software that is used to manage a development environment. Through the command line, you can grab any available OS, install it, configure it, run it, work inside of it, shut it down, and more.

---> Vagrant can be classified as a tool in the "Virtual Machine Management" category, while VirtualBox is grouped under "Virtualization Platform".

What is the relationship between your virtual machine and your local machine?

---> A virtual machine is a virtual representation, or emulation, of a physical computer. They are often referred to as a guest while the physical machine they run on is referred to as the host.

---> Virtualization makes it possible to create multiple virtual machines, each with their own operating system (OS) and applications, on a single physical machine.

Copy and paste text between your local computer and a VM:

---> Copying and pasting text to and from an x86 VM in the Secure Remote Access (SRA) browser client is possible, but there are limitations. There are two ways to copy and paste text between your local computer and the VM:

* Use keyboard shortcuts like Ctrl+C and Ctrl+V to copy and paste text. On a mac OS computer, use Cmd instead of Ctrlin your keyboard shortcuts (for example, Cmd+C instead of Ctrl+C).

* If the basic keyboard shortcuts do not work, use the VM Clipboard in the browser client toolbar to more reliably copy and paste text
Some of the features offered by Vagrant are:

* Boxes

* Up And SSH

* Synced Folders

---> On the other hand, VirtualBox provides the following key features:

* Portability

* No hardware virtualization required

* Guest Additions: shared folders, seamless windows, 3D virtualization

What vagrant provides and what virtual box provides?

---> Vagrant comes with support out of the box for VirtualBox, a free, cross-platform consumer virtualization product.

---> The VirtualBox provider is compatible with VirtualBox versions 4.0.x, 4.1.x, 4.2.x, 4.3.x, 5.0.x, 5.1.x, 5.2.x, 6.0.x, and 6.1.x. Other versions are unsupported and the provider will display an error message.

---> Please note that beta and pre-release versions of VirtualBox are not supported and may not be well-behaved.

---> VirtualBox must be installed on its own prior to using the provider, or the provider will display an error message asking you to install it. VirtualBox can be installed by downloading a package or installer for your operating system and using standard procedures to install that package.

Basic Provider Usage:

Boxes:

---> Vagrant boxes are all provider-specific. A box for VirtualBox is incompatible with the VMware Fusion provider, or any other provider.

---> A box must be installed for each provider, and can share the same name as other boxes as long as the providers differ. So you can have both a VirtualBox and VMware Fusion "bionic64" box.

Default Provider:

---> You typically do not need to specify --provider ever. Vagrant is smart enough about being able to detect the provider you want for a given environment.

Describe the difference between the messaging formats and why we might choose one over the other?

Types of Messaging:

We start with the most common forms of messaging, such as email and paging, and work toward some of the newer and more advanced formats including WAP Push, instant messaging, and application-to-application messaging.

Email:
--------

---> When it comes to messaging, email is the killer application. This is definitely true for PC users and more and more so for mobile and wireless users.

---> Every day, billions of email messages are sent; some users send and receive more than a hundred each day as a matter of course.

---> Email has become the preferred means of communication for many companies, providing a quick and easy way to move information between users, often in the form of standard text or business documents such as Microsoft Word or Excel.

Paging:
-----------

---> One of the earliest forms of messaging to mobile devices was paging. Paging typically involves a caller dialing a telephone number associated with the intended recipient of the page.

---> Once connected to the paging terminal, the person sending the page can enter a message that will be sent to the pager.

---> The message can be either numeric, alphanumeric, or voice, depending on the system being used. When the message is complete, the paging terminal converts the message into a pager code and sends it to a series of transmitters to which it is connected.

---> These transmitters then send out the message as a radio signal throughout the entire coverage area.

Short Message Service (SMS):
----------------------------------

---> The Short Message Service (SMS) was first introduced in Europe in 1991 as part of the GSM Phase 1 standard.

---> Since that time it has had tremendous success, with more than 1 billion messages sent around the world daily.

---> Though it continues to be more popular in European countries, SMS is catching on in North America as well, as more of the major wireless carriers add support for SMS and as SMS-capable devices start to proliferate in the marketplace. SMS is supported on digital wireless networks such as GSM, CDMA, and TDMA.

---> SMS makes it possible to send and receive short text messages to and from mobile telephones.

Enhanced Message Service (EMS):
--------------------------------------

---> The Enhanced Message Service (EMS) adds powerful new functionality to SMS. In addition to being able to send text, EMS allows users to send richer content, including pictures, animations, sounds, and formatted text.

---> EMS can be added to existing SMS infrastructures, saving operators from having to make large investments to add these new features.

---> This should help drive the adoption of EMS until more advanced messaging services, such as Multimedia Message Service (MMS) are rolled out in 2003 and 2004.

Multimedia Message Service (MMS):
------------------------------------

---> The Multimedia Message Service (MMS) takes the capabilities of EMS one step further, adding true richness to the message content.

---> In addition to the capability for pictures, formatted text, and sound introduced in EMS, MMS also provides support for voice, audio and video clips, and presentation information.

---> This is accomplished in a manner very similar to SMS: providing automatic immediate delivery for custom content, as well as store-and-forward capabilities when the recipient is unable to receive the message. MMS also adds support for email addressing, so messages can be sent to an email address from the MMS client.

Instant Messaging:
------------------------

---> Instant messaging (IM) is well positioned to be the next killer application for the wireless industry.

---> With the monumental growth rate of SMS, and more than 100 million desktop instant messaging users, the potential for wireless instant messaging is incredible.

---> It provides similar capabilities to other two-way messaging technologies, such as paging, SMS, and email, with the addition of one significant feature: presence! Presence is so elemental to IM that this form of messaging is often referred to as Instant Messaging and Presence Services (IMPS).

What did netcat provide? Describe your answer Apache?

---> Netcat or NC is a utility tool that uses TCP and UDP connections to read and write in a network.

---> It can be used for both attacking and security. In the case of attacking. It helps us to debug the network along with investing it. It runs on all operating systems.

Getting Started with Netcat:

To start NC, the most basic option we can use the help command. This will show us all the options that we can use with Netcat. The help command is the following one: nc -h

Configuring Flume:

We have to configure the source, the channel, and the sink using the configuration file in the conf folder. The example given in this chapter uses a NetCat Source, Memory channel, and a logger sink.

NetCat Source:

---> While configuring the NetCat source, we have to specify a port while configuring the source. Now the source (NetCat source) listens to the given port and receives each line we entered in that port as an individual event and transfers it to the sink through the specified channel.

---> While configuring this source, you have to provide values to the following properties −

* channels

* Source type − netcat

* bind − Host name or IP address to bind.

* port − Port number to which we want the source to listen.

What is Netcat Used For?

Netcat can be a useful tool for any IT team, though the growth of internally managed network services and cloud computing make that particular environment a natural fit. Network and system administrators need to be able to quickly identify how their network is performing and what type of activity is occurring.

What is a symbolic link and why do we care about them with respect to Apache?

---> A symbolic link (or "symlink") is file system feature that can be used to create a link to a specific file or folder.

---> It is similar to a Windows "shortcut" or Mac "alias," but is not an actual file.

---> Instead, a symbolic link is a entry in a file system that points to a directory or file.

---> The system recognizes the symbolic link as the actual directory or file, providing a alternate way to access it.

---> Symbolic links are supported by Mac, Windows, and Unix, but are most commonly found on Unix systems, since Unix is known for having a large (and often confusing) hierarchy of directories.

---> To create a symlink in Unix, you can type a simple command at the command prompt using the syntax below.

ln -s [target directory or file] /[shortcut]

---> For example, you can create a symlink "/apachelogs" that points to "/usr/local/apache/logs" using the following command:

ln -s /usr/local/apache/logs /apachelogs

---> After entering the command above, you would be able to access the Apache logs directory by simply opening "/apachelogs."

How would you use the broadcast IP to send a message to all computers in the subnet?

Scenario: A connected device wants to send a message to all of the nodes on a given IP subnet.

---> That message could be asking about other computers on the subnet offering services, like computers running games that are trying to find each other; or for detecting other computers on the Windows network using a protocol like NBT (NetBIOS over TCP) (assuming there is not a Name Server in the network, and the computers must find each other by broadcasts).

---> At Layer 2, a computer can send a broadcast to all of the nodes in the same broadcast domain - almost always, the broadcast domain stops at the router, which only forwards relevant packets at Layer 3.

---> If you are trying to broadcast a message to all of the nodes in a Layer 3 subnet, however, you will use the “all 1’s” host address for that network, and send the packet to that IP address. (You do not need to be a member of that subnet to send a broadcast to it!)

---> If the subnet were 192.168.1.0/24, the network address is 192.168.1.0, and the broadcast address is 192.168.1.255.

---> Sending a packet to 192.168.1.255 will get routed until it reaches a router that is connected to that network.