CompTIA A+ (220-1001) Cert Prep 8: Internet and the Cloud

What are xxx reasons to use a Proxy server?

1) A list of Internet addresses that devices in your network should not be going to or receiving communications from can be added to the proxy server. 2) A proxy server can look for keywords, attachments, etc., that should not be leaving or entering the local network and stop those transmissions. 3)

What band does Zigbee run in to control home automation?

2.4 GHz, because it does not need a lot of bandwidth.

How can you mitigate the affects of Split Tunneling?

3rd party VPN products have more advanced settings than standard operating system VPN settings, so more options are available to customize your VPN connections.

What is a MAN?

A Metropolitan Area Network is a WAN made up of multiple LANs all in a similar regional area.

What is a PAN?

A Personal Area Network is a Bluetooth network that is a point to point connection between 2 Bluetooth capable devices.

Describe a Type 2 Hypervisor.

A Type 2 hypervisor installs on top of the operating system that is installed on the host machine. The virtual machines then run on top of that hypervisor. VirtualBox is a Type 2 hypervisor.

What is a VPN?

A Virtual Private Network is a way to securely tunnel through the public Internet to get to your local home network. When properly connected via a VPN - no matter where you are in the world - it will be like you are sitting at your local home office. You'll have access to local file shares, printers, etc.

What is a WAN?

A Wide Area Network that is made up of multiple LANS each with their own network IDs, and all of the LANs are connected together by one or more routers.

What is a Virtual Machine?

A completely self-contained computer that is running within a host operating system.

What happens during FTP's Active mode?

A data request is sent out from the client over FTP's standard Port 21, but when the data is sent back, the FTP server sends it back on Port 20 or Port 21. Active mode is about 5 times faster than passive mode, but it is natively blocked by most routers because the original request was sent out on Port 21.

What is the most obvious different between a broadband connection and a dial-up connection?

A dial-up connection has to be manually connected by the user before it is active, while broadbands connections are always connected to the Internet.

What is the difference between a Private cloud environment and a Public cloud environment?

A private cloud is just accessible by you, your organization, or whoever you allow to have access to it. A public cloud is accessible to the public and is where anyone can access SaaS, IaaS, and PaaS.

How do Cable broadband connections work?

A standard F-type threaded connector comes into the cable box, and it has an RJ-45 connector that then sends the Internet connection to the local router or switch. There is also a separate F-type connector if you want to connect that cable box to your television as well.

What are 4 ways you can authenticate from your remote device in order to securely connect to your VPN?

A username and password, a smart card, a one-time password, or a local certificate.

What is one distinguishing factor that describes a LAN?

All devices in a LAN will share the same network ID.

What 3 type of connections are used to talk to almost all Internet of Things - IoT - devices?

Almost all IoT devices are wireless, so they will use the 802.11 protocols, Zigbee, which is used mostly for home automation, and Z-wave.

Generally speaking, what is "The Cloud"?

Anytime you access a remote, physical computer by its IP address.

What is Software as a Service, or SaaS?

Anytime you access a software program over the Internet, your are experiencing software as a service. Examples include Google Docs, Office 365, etc.

What are Streaming Applications?

Applications such as Microsoft Office applications, online games, etc., that are accessed over the Internet, rather than locally installed on your device. You don't get the full functionality of a robust program because it isn't being actually installed, but for things like viewing, making simple changes, or playing a game, it is a good option.

Does email always use ports 25, 110, and 143?

As far as CompTIA is concerned, yes. However, in the real world, there are random, secure ports, that are actually used to send and receive email.

What does the On Demand Resources cloud benefit mean?

As peaks in website traffic are created due to seasonal events, such as the SuperBowl, Christmas, or increases in traffic due to successful business practices happen, you can temporarily increase your cloud offerings as needed, and then very easily scale back down afterward.

What are the 2 types of DSL?

Asymmetric DSL and Symmetric DSL.

What do both POP3 and IMAP do?

Both protocols are are used to bring email down to an email client.

What settings can you change that will make all web browsers on a computer use the local proxy server?

Changing the LAN Settings from the Internet Options dialogue box will affect all web browsers on that local system.

What protocol is used by cable broadband?

DOCSIS is Data Over Cable Service Interface Specification.

What is DSL?

Digital Subscriber Line is a digital signal that piggybacks on top of an analog telephone signal.

When installing a virtual machine, what is the difference between a fixed hard drive or dynamically allocated?

Dynamically allocated means that whenever you shut off that virtual machine, whatever hard drive space that was allocated for the VM - but not physically used - is recovered by the host operating system. If you choose a fixed hard drive during set-up, that hard drive space on the host machine stays allocated to the VM, even if it is not running.

What are modern DSL signals carried through?

Fiber optic lines that carry DSL signals over the fiber connection in the GB per second speed ranges.

Describe FTP.

File Transfer Protocol is a non-secure file transfer protocol that uses Port 21. It can be accessed via FTP clients, or by just using the ftp:// addressing scheme in a web browser. Secure FTP, or SFTP uses Port 22.

What is a security benefit of using virtual machines?

If a virtual machine gets hacked or compromised, all you have to do to recover from the attack is turn off the virtual machine, and then turn it right back on again.

What is the drawback to using NAT on a virtual machine?

If you choose that option, you can only have one network outside of the network that is running on the host machine. This can be overcome by using NatNetworking.

What are virtual desktops?

In a virtual desktop infrastructure (VDI) environment, desktop operating systems and applications are virtually located and managed on a centralized, remote server. End users' data resides on that server and is centrally managed.

What is important port-specific information that you need to set up when configuring your Internet Options to use a proxy server?

In the Advanced dialogue box, you can specify which ports to use for things such as port 443 for secure web browsing, port 21 for FTP, etc.

What speed ranges have cable broadband supported over the years?

In the past, 1.5 Mbps upload and 10 Mbps download, while modern speeds of 50 Mbps upload and 100 Mbps download are common. Some connections even offer GB level uploads and downloads.

What is Infrastructure as a Service, or IaaS?

In the simplest terms, it is creating your own computers, servers, and other hardware and software in a 100% virtualized environment. Services such as Amazon Web Service will let you literally create a computing environment from scratch, and it is completely virtual and hosted in the cloud. You can choose the type and number of CPU's you want, how much mass storage you need, what type of networking and firewall environment you want, what operating system and software you want installed. It is completely customizable and costs a fraction of what it would cost to do those same things locally with your own physical hardware.

What is ISDN?

Integrated Services Digital is another type of dial-up Internet connection. It does not use a modem, however, but rather a physical terminal adapator that creates a completely digital signal that is sent and received by the computer. It rans at 64 kbps or 128 kbps, as opposed to standard dial-up which runs at 56 kbps.

What does the DOCSIS protocol allow to happen?

It allows the supporting hardware to provide both a data connection for the Internet as well as a television programming over the same connection.

What happens when you "bridge" a virtual machine to the network card of the host machine?

It essentially connects the virtual machine to the host network, including using the same physical ethernet network card.

Describe a Type 1 Hypervisor.

It installs on top of the actual hardware of the host machine - not the host machine's operating system. The virtual machines then run on top of that hypervisor.

What is NatNetworking?

It is a way to set up multiple, separate networks for different virtual machines that are all running on the host machine.

What happens to your IP address after you log into your local network via VPN?

It is just like you logged into your local network from home - your device will now be configured via DHCP with an IP address from the DHCP pool of your home network.

What does SMTP do?

It is the protocol we use to send email up to an SMTP server.

What was a DB-25 serial connector used for on older modems?

It would normally have a DB-9 serial connection on the other end that plugged into a computer in order to send and receive the digital signals from a modem when using a dial-up POTS or PSTN connection.

How do you manually set up a device to send and receive email.

Just add whatever account(s) you want to use, input the outgoing SMTP server address and the incoming POP3 or IMAP4 server address, and whatever login credentials you are given by your email provider.

How can you overcome the problem of Active mode FTP servers sending back data over Port 20 instead of the Port 21 that the request was originally initated from?

Modern routers support Port Triggering, which is a way to manually configure a router to allow applications to send data back over a different port than the port that the request was sent out on. This has to be configured inside the router's advanced settings, and it has to be configured for each individual application that it is needed for.

Do all CPUs support virtualization?

Most modern CPUs do, yes, but you sometimes have to go into the system settings in order to enable it.

What are NOCs?

Network Operations Centers that are owned by 3rd party vendors where all of the traffic from Tier 1 ISPs is managed.

Do the virtualized operating systems that are installed on top of a Type 2 hypervisor recognize the physical host machine?

No - the hypervisor software, such as VirtualBox, is between the virtualized operating systems and the physical host computer.

Do all routers support VPN?

No, but most modern routers do. The router must support the VPN Endpoint functionality which allows the VPN tunnel to be created from that router to the remote device that you are using to log into your home network.

Are NOCs just large server farms?

No. NOCs are heavily fortified facilities that are hardened against hurricanes, earthquakes, power outtages, etc., and they are even guarded by armed personnel due to the importance of their ability to keep the Internet up and running.

What is unique about the relationship between Tier 1 ISPs?

None of them are large enough to cover the entire U.S., so even though they are competitors, they have to work together.

How do you force the devices in your network to use the proxy server?

On your local router or your local firewall, you can block all out-going transmission requests from going out unless they come directly from the proxy server. In essence, every device in your local network has to talk to the proxy server first, rather than the router, and the proxy server is the only device that talks directly to the router.

What machines actually get put into the networks that are set up in NatNetworking?

Once you set up one or more NAT networks in the settings of VirtualBox, you can then go into the network settings for every single virtual machine and tell them which one of the NAT networks you want them to use.

What are the financial benefits of running virtual machines on host systems?

Ordinarily, every operating system would have to be installed on its own, physical dedicated computer. By virtualizing operating systems on host computers, significantly fewer actual computers need to be purchased, which also creates a significant energy savings. Not only are there fewer power-consuming computers running, but the environmental controls will not have to work as hard because not as much heat is being released since there aren't as many computers.

What are 3 common security protocols that are used by 3rd party VPN client tools?

PPTP, L2TP, and Ipsec.

What are the 2 modes that FTP uses?

Passive mode and Active mode.

What is Platform as a Service, or PaaS?

Platform as a Service is a very easy and inexpensive way for programmers, web developers, etc., to write and test code in whatever environment, operating systems, type of hardware, etc., that they want to test it on.

What is PPPoE?

Point to Point Protocol over Ethernet is how a device is configured to access a DSL Internet connection.

What is main drawback to using a proxy server?

Proxy servers or "proxy as a service" can be very costly.

How can proxy servers make local web browsing faster?

Proxy servers perform caching, so you can set up the local proxy server to cache the often used websites that devices in your network use frequently. The proxy server will cache the static parts of those web pages, and then just pull in new information from those sites as needed.

What are the 3 email protocols used on the Internet?

SMTP, which is Simple Mail Transport Protocol and runs on Port 25. POP, which is Post Office Protocol and runs on Port 110. IMAP, which is Internet Message Access Protocol and runs on Port 143.

What is the cloud benefit Rapid Elasticity?

Since cloud data is available remotely and does not require additional physical computers or servers at your physical location, it is simple to copy and/or move websites, services, databases, etc., to different cloud storage locations in order to expand their reach to different markets or geographic areas.

When setting up virtual machines, what is a good mass storage practice?

Since virtual machine files will be in GB sizes, it is best to keep them on an external or separate mass storage device than what the host operating system is installed on.

What is a networking benefit of using virtualization?

Since virtual machines are completely self-contained on the host computer, their networks are virtual as well, which means they can be 100% customized to run in whatever configuration is needed, and the possibilities for testing and experimentation are endless.

What are the 3 most popular voice-activated IoT devices?

Siri, Amazon Alexa, and Google Home.

When using cable broadband, can you use your own router?

Some ISPs will let you, but if they don't, technically it is very easy to set up your own router without them realizing it. You can clone the MAC address off of the ISP's router and manually enter it into your router, so from their perspective, they don't even know that you are using a different router.

What is a Hybrid cloud?

Some of the cloud environment is public, while some is private. For example, you could have a cloud environment set up for your organization that is private, but you allow public access to certain parts of it.

What is required to control IoT devices?

Some type of hub.

What band does Z-wave run in?

The 900 MHz band.

What does the VPN client installed on your device connect to back at your home network?

The WAN IP address of your home router.

What is a Hypervisor?

The actual host that runs a virtual machine.

What are Peering Agreements?

The agreements between competing Tier 1 ISPs to allow each other's Internet traffic to go through their competitor's networks in order to cover areas not covered by any individual Tier 1 provider.

In order to open a web page, what 2 devices must allow outgoing connections to Port 80, the http port?

The host-based firewall on the devices itself, and the router that the LAN is connected to. *

How is redundancy a huge benefit of using IaaS and other cloud services?

The major companies, such as Amazon Web Services, who offer these virtualized environments have extremely robust physical as well as electronic back up systems. The data itself is backed up redundantly, and there are also physically separated buildings where additional backups are kept, so even if one building is damaged, everything is still safe in another building.

Why is it that if a router is blocking incoming connections on Port 80, that end-user requests for web pages still get through the router?

The source port number from the requesting end-user is actually whatever random port was chosen for that web browsing session. The http protocol comes through Port 80, but the session port number is some other random number, such as 14421. *

Describe Symmetric DSL or ADSL.

The upload and download speeds are exactly the same.

Describe Asymmetric DSL or ADSL.

The upload speed is slower than the download speed.

How do you log into a PPPoE connection?

There is a username and password that are given to you by your ISP, and in the past, each computer that needed a connection to that PPPoE DSL had to pay for a separate DSL subscription. Today, modern routers understand the PPPoE protocol, and after the DSL signal is brought into the router, it can then be distributed to multiple different devices over LAN cables and/or wireless signals.

How much RAM do virtual machines use?

There is no set number, as it depends on the type of virtual machine you are installing, and what type of memory you think you'll be using based on what you plan to do with that virtual machine. Since virtual machines use the physical RAM of the host system, it is best for the host system to have as much installed RAM as possible.

How are proxy servers set up?

They are Application-specific, which means that any program on your devices that can reach the Internet have to be manually programmed to go to the proxy server. There is no one setting on a device that covers all incoming and outgoing transmissions, so proxy settings have to be put on each individual program that can reach the Internet.

What are Tier 2 Internet providers?

Tier 2 ISPs are not as big as Tier 1 providers, but their services still span very large areas. They often have to pay Tier 1 ISPs for Internet access, but in some cases there are peering agreements in place.

What are Tier 3 Internet providers?

Tier 3 ISPs are what most people will be familiar with, such as Comcast, AT&T, etc. These companies make their money by buying Internet services from Tier 2 or Tier 1 providers, and then reselling it to consumers.

What is one of the primary jobs of a firewall, whether it is software or hardware based?

To block ports to keep from allowing unwanted communication into a network or a computer.

For enterprise level virtualization, which type of hypervisor is usually used?

Type 1, because since it installs directly onto the host hardware - in essence becoming the computer's operating system - it is more efficient than Type 2 hypervisors.

What were the original up and download speeds of DSL?

Uploads between 768 kbps to 3 Mbps, and downloads between 1.5 Mbps and 7 Mbps.

What are common satellite broadband connection speeds today?

Uploads of 3 Mbps, and downloads of 25 Mbps or higher.

Name 4 Type 1 hypervisors.

VMWare, ESxI, Microsoft Hyper-V, and some open source options as well.

What are Tier 1 Internet providers?

Very large companies that provide Internet services to other, smaller companies. There are approximately 10 Tier 1 providers in the United Sates.

What is the difference between virtualization and emulation

Virtualization physically runs on the hardware and available resources of the host machine. Emulation is using software to pretend to have hardware that is not actually on the host machine.

What ports absolutely must be open on any given server, such as a file server, a print server, an email server, etc?

Whatever services are being offered by that server must be allowed as incoming port connection requests, or all traffic going to that server looking for those services would be blocked. For example, a web server must allow all incoming requests on Port 80 for http, and Port 443 for Secure http. *

What is a Community Cloud?

When multiple organizations pool their physical and financial resources to create and pay for a semt-private cloud environment that only the members of those organizations can access.

What is Split Tunneling?

When remotely using a VPN, your requests to go to public Internet addresses have to go all the way back into your home network through the router, get sent back out as a request just as if you were physically at your home network. Next, the Internet data has to once again go back into your home network because that is where the request came from, and then your home network sends that data to your remote location over the VPN tunnel.

What is one drawback to using satellite broadband?

When you first connect, sometimes there is latency as the signal travels back and forth between the dish on your roof and the satellite in orbit.

What is the difference between POP3 and IMAP?

When you use POP3, you have to manually configure all of your folders, email client configurations, etc., on every single machine that you use to access your email. IMAP keeps all of your folders and configurations in the cloud, so each time you log into your email from a different machine, you get all of the same settings, folders, etc.

What is the cloud benefit of Resource Pooling?

When your business or offerings are hosted virtually on physical machines in some remote locations, the physical machines that you pay to have access to can all share the same resources such as electricity, HVAC, etc., which ultimately saves you money over having to pay for multiple instances of those resources.

Can you get home Internet services using the 802.11 standards?

Yes, there are companies now that will install a highly directional yagi antenna that points to one of their towers and you can wirelessly bring Internet into your home over that connection.

Can you allow devices in your local network to avoid using the proxy server?

Yes, there is a setting to skip the proxy server for local addresses, and in the advanced settings you can also specify IP addresses that can be reached without going through the proxy server.

What happens when you use NAT to set up the network on your virtual machine?

You create a virtual router with a "WAN" IP address that points to the actual network that is running on the host machine, but all of the devices inside the virtual machine will be on their own, separate private network.

What is something you have to consider when it comes to storing data in the cloud that multiple people will have access to.

You have to consider how the cloud provider that you are using handles synchronization if 2 people open the same file at the same time. Each provider has their own way of dealing with it, so you have to find out how your provider handles that situation.

What is important to remember about setting up NatNetworking in VirtualBox?

You have to enable it in the settings of the VirtualBox hypervisor itself, not just the individual virtual machine's settings.

How did the old dial-up connections work?

You would receive a telephone number from your ISP which was the telephone number that your modem would call in order to be connected to the Internet over a COM port on your computer. Modern operating systems still support the set-up and use of dial-up services.

Name 4 cloud-based applications that are specific to the organizations that created them.

iCloud, OneDrive, Google Drive, and Drop Box.