Networking 101 and Top 20 AWS Certified Advanced Networking Specialty Questions and Answers Dumps

The AWS Certified Advanced Networking – Specialty (ANS-C00) examination is intended for individuals who perform complex networking tasks. This examination validates advanced technical skills and experience in designing and implementing AWS and hybrid IT network architectures at scale.

The exam covers the following domains:

Domain 1: Design and Implement Hybrid IT Network Architectures at Scale – 23%

Domain 2: Design and Implement AWS Networks – 29%

Domain 3: Automate AWS Tasks – 8%

Domain 4: Configure Network Integration with Application Services – 15%

Domain 5: Design and Implement for Security and Compliance  – 12%

Domain 6: Manage, Optimize, and Troubleshoot the Network – 13%

Below are the top 20 Top 20 AWS Certified Advanced Networking – Specialty  Practice Quiz including Questions and Answers and References

Question 1: What is the relationship between private IPv4 addresses and Elastic IP addresses?

ANSWER1:

C

Notes/Hint1: 

The relationship between private IPv4 addresses and Elastic IP addresses is one-to-one.

Reference1: IPv4 and Elastic IP

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Question 2: A company’s on-premises network has an IP address range of 11.11.0.0/16. Only IPs within this network range can be used for inter-server communication. The IP address range 11.11.253.0/24 has been allocated for the cloud. A network engineer needs to design a VPC on AWS. The servers within the VPC should be able to communicate with hosts both on the internet and on-premises through a VPN connection. Which combination of configuration steps meet these requirements? (Select TWO.)

A) Set up the VPC with an IP address range of 11.11.253.0/24.

B) Set up the VPC with an RFC 1918 private IP address range (for example, 10.10.10.0/24). Set up a NAT gateway to do translation between 10.10.10.0/24 and 11.11.253.0/24 for all outbound traffic.

C) Set up a VPN connection between a virtual private gateway and an on-premises router. Set the virtual private gateway as the default gateway for all traffic. Configure the on-premises router to forward traffic to the internet.

D) Set up a VPN connection between a virtual private gateway and an on-premises router. Set the virtual private gateway as the default gateway for traffic destined to 11.11.0.0/24. Add a VPC subnet route to point the default gateway to an internet gateway for internet traffic.

E) Set up the VPC with an RFC 1918 private IP address range (for example, 10.10.10.0/24). Set the virtual private gateway to do a source IP translation of all outbound packets to 11.11.0.0/16.

ANSWER2:

A and C

Notes/Hint2:

The VPC needs to use a CIDR block in the assigned range (and be non-overlapping with the data center). All traffic not destined for the VPC is routed to the virtual private gateway (that route is assumed) and must then be forwarded to the internet when it arrives on-premises. B and E are incorrect because they are not in the assigned range (non-RFC 1918 addresses can be used in a VPC). D is incorrect because it directs traffic to the internet through the internet gateway.

Reference1: CIDR block 

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Question 3: Tasks running on Amazon EC2 Container Service (Amazon ECS) can use which mode for container networking (allocating an elastic networking interface to each running task, providing a dynamic private IP address and internal DNS name)?

ANSWER3:

A

Notes/Hint3:

Tasks running an Amazon EC2 Container Service can use awsvpc for container networking.

Reference3: Task Networking with the awsvpc Network Mode

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Question 4: A network engineer needs to design a solution for an application running on an Amazon EC2 instance to connect to a publicly accessible Amazon RDS Multi-AZ DB instance in a different VPC and Region. Security requirements mandate that the traffic not traverse the internet. Which configuration will ensure that the instances communicate privately without routing traffic over the internet?

A) Create a peering connection between the VPCs and update the routing tables to route traffic between the VPCs. Enable DNS resolution support for the VPC peering connection. Configure the application to connect to the DNS endpoint of the DB instance.

B) Create a gateway endpoint to the DB instance. Update the routing tables in the application VPC to route traffic to the gateway endpoint.

C) Configure a transit VPC to route traffic between the VPCs privately. Configure the application to connect to the DNS endpoint of the DB instance.

D) Create a NAT gateway in the same subnet as the EC2 instances. Update the routing tables in the application VPC to route traffic through the NAT gateway to the DNS endpoint of the DB instance.

ANSWER4:

A

Notes/Hint4:

Configuring DNS resolution on the VPC peering connection will allow queries from the application VPC to resolve to the private IP of the DB instance and prevent routing over the internet. B is incorrect because Amazon RDS is not supported by gateway endpoints. C and D are incorrect because the database endpoint will resolve to a public IP and the traffic will go over the internet.

Reference4: DNS Resolution on the VPC Peering connection

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Question 5: Management has decided that your firm will implement an AWS hybrid architecture. Given that decision, which of the following is a petabyte-scale data transport solution that uses secure appliances to transfer large amounts of data into and out of the AWS Cloud?

ANSWER5:

B

Notes/Hint5:

AWS Snowball is a petabyte-scale data transport solution that uses secure appliances to transfer large amounts of data into and out of the AWS Cloud.

Reference5: AWS Snowball 

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Question 6: A company has implemented a critical environment on AWS. For compliance purposes, a network engineer needs to verify that the Amazon EC2 instances are using a specific approved security group and belong to a specific VPC. The configuration history of the instances should be recorded and, in the event of any compliance issues, the instances should be automatically stopped. What should be done to meet these requirements?

A) Enable AWS CloudTrail and create a custom Amazon CloudWatch alarm to perform the required checks. When the CloudWatch alarm is in a failed state, trigger the stop this instance action to stop the noncompliant EC2 instance.

B) Configure a scheduled event with AWS CloudWatch Events to invoke an AWS Lambda function to perform the required checks. In the event of a noncompliant resource, invoke another Lambda function to stop the EC2 instance.

C) Configure an event with AWS CloudWatch Events for an EC2 instance state-change notification that triggers an AWS Lambda function to perform the required checks. In the event of a noncompliant resource, invoke another Lambda function to stop the EC2 instance.

D) Enable AWS Config and create custom AWS Config rules to perform the required checks. In the event of a noncompliant resource, use a remediation action to execute an AWS Systems Manager document to stop the EC2 instance.

ANSWER6:

D

Notes/Hint6:

AWS Config provides a detailed view of the configuration of AWS resources in a user’s AWS account. Using AWS Config rules with AWS Systems Manager Automation documents can automatically remediate noncompliant resources

Reference6: AwS Config

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Question 7: A previous administrator configured an inbound security group rule for port 80 (TCP) of 0.0.0.0/0 on the web server. What does this allow?

ANSWER7:

C

Notes/Hint7:

This rule allows all inbound traffic to port 80.

Reference7: Inbound Traffic

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Question 8: A company is extending its on-premises data center to AWS. Peak traffic is expected to range between 1 Gbps and 2 Gbps. A network engineer must ensure that there is sufficient bandwidth between AWS and the data center to handle peak traffic. The solution should be highly available and cost effective. What should be implemented to address these needs?

A) Deploy a 10 Gbps AWS Direct Connect connection with an IPsec VPN backup.

B) Deploy two 1 Gbps AWS Direct Connect connections in a link aggregation group.

C) Deploy two 1 Gbps AWS Direct Connect connections in a link aggregation group to two different Direct Connect locations.

D) Deploy a 10 Gbps AWS Direct Connect connection to two different Direct Connect locations.

ANSWER8:

C

Notes/Hint8:

Two AWS Direct Connect connections with link aggregation groups in two different Direct Connect locations are required to provide sufficient bandwidth with high availability. If one Direct Connect location experiences a failure, the two Direct Connect connections in the second Direct Connect location will provide backup. All of the other options would be unable to handle the peak traffic if a connection was lost.

Reference8: Direct Connect connections with link aggregation

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Question 9: Which of the following DNS record types is not supported by Amazon Route 53?

E) AAAA

F) SRV

ANSWER9:

A

Notes/Hint9:

DNAME is not supported by Amazon Route 53.

Reference9: Route53 record types

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Question 10: A network engineer needs to limit access to the company’s Amazon S3 bucket to specific source networks. What should the network engineer do to accomplish this?

A) Create an ACL on the S3 bucket, limiting access to the CIDR blocks of the specified networks.

B) Create a bucket policy on the S3 bucket, limiting access to the CIDR blocks of the specified networks using a condition statement.

C) Create a security group allowing inbound access to the CIDR blocks of the specified networks and apply the security group to the S3 bucket.

D) Create a security group allowing inbound access to the CIDR blocks of the specified networks, create a S3 VPC endpoint, and apply the security group to the VPC endpoint.

ANSWER10:

B

Notes/Hint10:

An Amazon S3 bucket policy that uses a condition statement will support restricting access if the request originates from a specific range of IP addresses. A is incorrect because an S3 ACL does not support IP restrictions. C is incorrect because security groups cannot be applied to S3 buckets. D is incorrect because security groups cannot be applied to an S3 VPC endpoint.

Reference10: S3 Bucket Policy

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Question 11: AWS Direct Connect has two separate billable charges: port-hours and data transfer. Pricing is per port-hour consumed for each port type. How are partial port-hours handled?

ANSWER11:

A

Notes/Hint11:

Partial port-hours are billed as full hours.

Reference11: AWS Direct Connect billing

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Question 12: A company’s compliance requirements specify that web application logs must be collected and analyzed to identify any malicious activity. A network engineer also needs to monitor for remote attempts to change the network interface of web instances. Which services and configurations will meet these requirements?

A) Install the Amazon CloudWatch Logs agent on the web instances to collect application logs. Use VPC Flow Logs to send data to CloudWatch Logs. Use CloudWatch Logs metric filters to define the patterns to look for in the log data.

B) Configure AWS CloudTrail to log all management and data events to a custom Amazon S3 bucket and Amazon CloudWatch Logs. Use VPC Flow Logs to send data to CloudWatch Logs. Use CloudWatch Logs metric filters to define the patterns to look for in the log data.

C) Configure AWS CloudTrail to log all management events to a custom Amazon S3 bucket and Amazon CloudWatch Logs. Install the Amazon CloudWatch Logs agent on the web instances to collect application logs. Use CloudWatch Logs Insights to define the patterns to look for in the log data.

D) Enable AWS Config to record all configuration changes to the web instances. Configure AWS CloudTrail to log all management and data events to a custom Amazon S3 bucket. Use Amazon Athena to define the patterns to look for in the log data stored in Amazon S3.

ANSWER12:

C

Notes/Hint12:

Web application logs are internal to the operating system, and Amazon CloudWatch Logs Insights can be used to collect and analyze the logs using the CloudWatch agent. AWS CloudTrail monitors all AWS API activity and can be used to monitor particular API calls to identify remote attempts to change the network interface of web instances.

Reference12: Amazon CloudWatch Logs insights

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Question 13: What is the maximum number of security groups that you can create for each VPC?

E) 500

F) 5

G) Unlimited

ANSWER13:

D

Notes/Hint13:

250 is the maximum number of security groups that you can create for each VPC.

Reference13: Quotas

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Question 14: A company has an application that processes confidential data. The data is currently stored in an on premises data center. A network engineer is moving workloads to AWS, and needs to ensure confidentiality and integrity of the data in transit to AWS. The company has an existing AWS Direct Connect connection. Which combination of steps should the network engineer perform to set up the most cost-effective connection between the on-premises data center and AWS? (Select TWO.)

A) Attach an internet gateway to the VPC.

B) Configure a public virtual interface on the AWS Direct Connect connection.

C) Configure a private virtual interface to the virtual private gateway.

D) Set up an IPsec tunnel between the customer gateway and a software VPN on Amazon EC2.

E) Set up a Site-to-Site VPN between the customer gateway and the virtual private gateway.

ANSWER14:

B and E

Notes/Hint14:

Setting up a VPN over an AWS Direct Connect connection will secure the data in transit. The steps to do so are: set up a public virtual interface and create the Site-to-Site VPN between the data center and the virtual private gateway using the public virtual interface. A is incorrect because it would send traffic over the public internet. C is not possible because a public virtual interface is needed to announce the VPN tunnel IPs. D is incorrect because it would not take advantage of the already existing Direct Connect connection.

Reference14: VPN over Direct Connect

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Question 15: A site you are helping create must use Adobe Media Server and the Adobe Real-Time Messaging Protocol (RTMP) to stream media files. When it comes to AWS, an RTMP distribution must use which of the following as the origin?

ANSWER15:

D

Notes/Hint15:

 An RTMP distribution must use S3 bucket as the origin.

Reference15: S3 Bucket as origin

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Question 16: A company is creating new features for its ecommerce website. These features will be deployed as microservices using different domain names for each service. The company requires the use of HTTPS for all its public-facing websites. The application requires the client’s source IP. Which combination of actions should be taken to accomplish this? (Select TWO.)

A) Use a Network Load Balancer to distribute traffic to each service.

B) Use an Application Load Balancer to distribute traffic to each service.

C) Configure the application to retrieve client IPs using the X-Forwarded-For header.

D) Configure the application to retrieve client IPs using the X-Forwarded-Host header.

E) Configure the application to retrieve client IPs using the PROXY protocol header.

ANSWER16:

B and C

Notes/Hint16:

An Application Load Balancer supports host-based routing, which is required to route traffic to different microservices based on the domain name. X-Forwarded-For is the correct request header to identify the client’s source IP address.

Reference16: Host based routing

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Question 17: What is the maximum number of connections you can have in a LAG (Link Aggregation Group)?

ANSWER17:

A

Notes/Hint17:

The maximum number of connections that a LAG can have is 4.

Reference17: Link Aggregation Group

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Question 18: A network engineer is architecting a high performance computing solution on AWS. The system consists of a cluster of Amazon EC2 instances that require low-latency communications between them. Which method will meet these requirements?

A) Launch instances into a single subnet with a size equal to the number of instances required for the cluster.

B) Create a cluster placement group. Launch Elastic Fabric Adapter (EFA)-enabled instances into the placement group.

C) Launch Amazon EC2 instances with the largest available number of cores and RAM. Attach Amazon EBS Provisioned IOPS (PIOPS) volumes. Implement a shared memory system across all instances in the cluster.

D) Choose an Amazon EC2 instance type that offers enhanced networking. Attach a 10 Gbps non-blocking elastic network interface to the instances.

ANSWER18:

B

Notes/Hint18:

Cluster placement groups and Elastic Fabric Adapters (EFAs) are recommended for high performance computing applications that benefit from low network latency, high network throughput, or both. A is incorrect because the size of a subnet has no impact on network performance. C is incorrect because an Amazon EBS volume cannot be shared between Amazon EC2 instances. D is only half the solution because the enhanced networking affects the network behaviour of an EC2 instance but not the network infrastructure between instances.

Reference18: Cluster placement groups

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Question 19: What is the maximum number of security groups that can be associated with each network interface?

E) 2

ANSWER2:

C

Notes/Hint19:

The default number of security groups that can be associated with each network interface is 5. The maximum is 16. This quota is enforced separately for IPv4 rules and IPv6 rules. 

Reference19: maximum number of security groups per network interface

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Question 20: A company’s internal security team receives a request to allow Amazon S3 access from inside the corporate network. All external traffic must be explicitly allowed through the corporate firewalls. How can the security team grant this access?

A) Schedule a script to download the Amazon S3 IP prefixes from AWS developer forum announcements. Update the firewall rules accordingly.

B) Schedule a script to download and parse the Amazon S3 IP prefixes from the ip-ranges.json file. Update the firewall rules accordingly.

C) Schedule a script to perform a DNS lookup on Amazon S3 endpoints. Update the firewall rules accordingly.

D) Connect the data center to a VPC using AWS Direct Connect. Create routes that forward traffic from the data center to an Amazon S3 VPC endpoint.

ANSWER20:

B

Notes/Hint20:

The ip-ranges.json file contains the latest list of IP addresses used by AWS. AWS no longer posts IP prefixes in developer forum announcements. DNS lookups would not provide an exhaustive list of possible IP prefixes. D would require transitive routing, which is not possible.

Reference20: ip-range.json

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I- SOURCE:

1- Djamga Cloud Networking Youtube Channel

2- Prepare for Your AWS Certification Exam

II- LATEST NETWORKING NEWS:

III-LATEST NETWORKING JOBS:


IV-CLOUD NETWORKING Q&A:

V- HOW WIFI WORKS:

How Wi-Fi Works: From Electricity to Information

What is Wi-Fi? Where did it come from?

Wi-Fi is a brand name for wireless networking standards. Wi-Fi lets devices communicate by sending and receiving radio waves.

In 1971, the University of Hawaii demonstrated the first wireless data network, known as ALOHAnet. In 1985, the US FCC opened the ISM radio bands for unlicensed transmissions. After 1985, other countries followed, and more people started experimenting. In 1997 and 1999, the IEEE ratified the first international wireless networking standards. They were called 802.11-1997, 802.11b, and 802.11a. The technology was amazing, but the names were not.

In 1999, the brand-consulting firm Interbrand created the logo and suggested Wi-Fi as the name. Wi-Fi was a pun on hi-fi, referring to high-fidelity audio. Wi-Fi was easier to remember than 802.11, and we've been stuck with the name since. The official name is Wi-Fi, but most people don’t capitalize it or include the hyphen. Wi-Fi, WiFi, Wifi, wifi, and 802.11 all refer to the same thing. In the early days, Wi-Fi was used as shorthand for Wireless Fidelity, but it isn’t officially short for anything. According to the Wi-Fi Alliance, Wi-Fi is Wi-Fi.

What does Wi-Fi do? How does Wi-Fi work?

Wi-Fi transmits data using microwaves, which are high-frequency radio waves. Wi-Fi is more complicated than FM radio, but the basic underlying technology is the same. They both encode information into radio waves, which are received and decoded. FM radio does this for sound, Wi-Fi does this for computer data. So how can we use radio waves to send sound, or information?

At a basic level, you can think of two people holding a jump rope. One person raises and lowers their arm quickly, creating a wave. With Wi-Fi, this person would represent your Wi-Fi router, or wireless access point. Keeping the same up and down motion is known as a carrier wave. The person on the other end is the client device, such as a laptop or cell phone. When a wireless client joins the network and senses the carrier wave, it starts listening and waits for small differences in the signal.

In our example, you can imagine feeling the jump rope going up and down, and then receiving a single motion to the right. That single motion to the right can be interpreted as a binary number 1. A motion to the left would be a binary 0. Chain enough 1’s and 0’s together and you can represent complicated things, like all the data on this webpage.

It sounds like magic, but it’s not only Wi-Fi that works this way. Bluetooth, 4G, 5G, and most wireless transmissions work by manipulating waves to transfer electrical signals through the air. A deeper, better question than “How does Wi-Fi work?” is “How do wireless transmissions work?”

If you want a better answer, you need to have a basic understanding of a few things:

    • Fundamental physics of electricity and magnetism

    • Electromagnetic radiation, radio waves, and antennas

  • How wired networks transmit data

I tried my best to keep this understandable, and laid out in a way that makes sense. This stuff is complicated, and hard to explain. That is why there are so many bad explanations of how Wi-Fi works out there.

This isn't going to be a light and breezy discussion. Each of these topics could be an entire college course, so forgive me for simplifying where possible. Use Wikipedia and other resources to fill in the gaps, or to clarify something I glossed over. As always, corrections and feedback are welcomed.

Let’s dive in the deep end and cover the physics first. If you’re not familiar with fundamental physics, Wikipedia is an amazing resource. The key terms highlighted in blue are links to Wikipedia articles which explain further.

Wi-Fi Physics 101: Electricity and Magnetism
    • Matter is made up of atoms.

    • A positively or negatively charged particle creates an electric field.

    • An electric field exerts force on other charges around it, attracting or repelling them.

    • Electrical current is a flow of negatively charged electrons through a conductive material, like a wire.

    • Electrical current flowing through a wire creates a magnetic field. This is how electromagnets work.

    • In 1867, James Clerk Maxwell discovered that light, magnetism, and electricity are related.

    • He predicted the existence of electromagnetic waves.

    • His equations describe how electric and magnetic fields are generated by charges, currents, and other field changes.

    • This is known as the 2nd great unification of physics, behind Sir Issac Newton.

    • In 1887, Heinrich Hertz was the first to prove the existence of electromagnetic waves. People thought that was so cool, they used his last name as the unit for a wave’s frequency.

    • Since visible light is an electromagnetic wave, this is how we can see the sun, or distant stars.

    • This is also how we heard Neil Armstrong say “One small step for man…” live from the moon.

    • The warmth you feel from sunlight is due to the radiant energy sunlight contains. All electromagnetic waves have radiant energy.

    • Examples of electromagnetic waves: Visible light, radio waves, microwaves, infrared, ultraviolet, X-rays, and gamma rays.

  • Wi-Fi is an example of a radio wave, specifically a microwave. Microwaves are high-energy radio waves.

Electromagnetic Waves

Electromagnetic waves come in a wide range of forms. The type of wave is categorized by wavelength and frequency.

Wavelength is a measure of the distance over which the wave's shape repeats. In a typical continuous sine wave like Wi-Fi, every time a wave goes from peak to valley to peak, we call that a cycle. The distance it takes to complete one cycle is its wavelength.

Frequency is a measure of how many cycles the wave makes per second. We use Hertz (Hz) as the measure of frequency, 1 Hz is one cycle per second. The more common MHz and GHz are for millions, or billions, of cycles per second.

Imagine waves on a beach. On calm days the waves are small, and come in slowly. On a windy day the waves have more energy, come in faster, and have less distance between them. Higher energy, higher frequency, shorter wavelength. Unlike ocean waves, electromagnetic waves move at the speed of light. Since their speed is constant, their wavelength and frequency are inverse. As wavelength goes up, frequency does down. If you multiply the wavelength and frequency, you will always get the same value — the speed of light, the speed limit of the universe.

You can graph all the various kinds of electromagnetic waves, with the lowest energy on the left, and the highest energy on the right. We call this the electromagnetic spectrum. I’m not going to cover the entire electromagnetic spectrum, since we are mainly interested in Wi-Fi’s microwaves, and how we can use them to send data wirelessly.

Starting from the left, we have the low-energy waves we call radio. Opinions vary, but I’m going with Wikipedia’s broad definition that radio waves cover from 30 Hz, up to 300 GHz. Compared to the rest of the spectrum, radio’s wavelengths are long, their frequency is slow, and energy is low. Within radio waves, there is a separate category we call microwaves.

Microwaves fall within the broader radio wave range. At a minimum, microwaves cover 3 GHz to 30 GHz, but some people say microwaves extend further than that. The specific range depends on who you ask, but generally you can think of Microwaves as high-frequency radio waves.

Microwaves are used in microwave ovens, Bluetooth, Wi-Fi, your cell phone’s 4G or 5G connection, and lots of other wireless data transmissions. Their higher energy, shorter wavelength, and other properties make them better for high-bandwidth transfers than traditional, lower-powered radio waves.

All waves can be modulated by varying either the amplitude (strength), frequency or phase of the wave. This is what allows Wi-Fi, and any other wireless technology, to encode data in a wireless signal.

Wired Networking Transmissions

Before we cover how wireless data transmission works, we need to understand how wired data transmission works. In wired Ethernet networks, we use the copper inside Ethernet cables to transmit electrical signals. The conductive copper transfers the electrical current applied at one end, through the wire, to the other side.

A typical example would be a PC plugged into an Ethernet switch. If the PC wants to transfer information, it converts binary digits to electrical impulses. On, off, on, off. It sends a specific pattern of 1’s and 0’s across the wire, which is received on the other end. Ethernet is the neighborhood street of the networking world. It's great for getting around the local area, but you’ll need to jump on the highway if you want to go further.

The highway of the networking world is fiber optic cabling. Just like how Ethernet transfers electrical current, we can do the same thing with lasers and fiber optic cables. Fiber optic cables are made of bendable glass, and they provide a path for light to be transmitted. Since fiber optics require lasers, special transceivers are required at each end. Compared to Ethernet, Fiber optic cables have the advantage of having a longer range, and generally a higher capacity.

Fiber optic cabling carries a big portion of global Internet traffic. We have a wide array of fiber optic cabling over land, and sea. Those connections are what allow you to communicate with someone on the other side of the country, or the other side of the world. This is possible because these transmissions happen at the speed of light.

Here’s where things get fun. Just like how Ethernet and fiber optic cabling take an electrical impulse or beam of light from A to B, we can do the same thing with radios, antennas, and radio waves.

Radios, Antennas, and Wireless Networking

Now that we have a rough common understanding of electromagnetic waves and wired data transmission, how can we transmit data wirelessly? The key is an antenna. Antennas convert electricity into radio waves, and radio waves into electricity. A basic antenna consists of two metal rods connected to a receiver or transmitter.

When transmitting, a radio supplies an alternating electric current to the antenna, and the antenna radiates the energy as electromagnetic waves. When receiving, an antenna reverses this process. It intercepts some of the power of a radio wave to produce an electrical current, which is applied to a receiver, and amplified. Receiving antennas capture a fraction of the original signal, which is why distance, antenna design, and amplification are important for a successful wireless transmission.

If you have a properly tuned, powerful antenna, you can send a signal 1000s of kilometers away, or even into space. It's not just Wi-Fi, this is what makes satellites, radar, radio, and broadcast TV transmissions work too. Pretty cool, right?

How Wi-Fi Works: From Electricity to Information
    • An intricate pattern of electrons representing computer data flow into your Wi-Fi router, or wireless access point.

    • The access point sends that pattern of electrons to an antenna, generating an electromagnetic wave.

    • By alternating between a positive to negative charge, the wire inside of an antenna creates an oscillating electric and magnetic field. These oscillating fields propagate out into space as electromagnetic waves, and are able to be received by anyone in range.

    • Typical Wi-Fi access points have omnidirectional antennas, which make the wave propagate in all horizontal directions.

    • This wave travels through the air and hits a receiving antenna which reverses the process, converting the radiant energy in the radio wave back into electricity.

    • The electric field of the incoming wave pushes electrons back and forth in the antenna, creating an alternating positive and negative charge. The oscillating field induces voltage and current, which flows to the receiver.

    • The signal is amplified and received, either to the client device or to an Ethernet connection for further routing.

    • A lot of the wave’s energy is lost along the way.

    • If the transmission was successful, the electrical impulses should be a good copy of what was sent.

    • If the transmission wasn’t successful, the data is resent.

  • When the information is received on the other end, it is treated the same as any other data on the network.

More Fun Wi-Fi Facts
    • Wi-Fi has redundancy built-in. If you wanted to send “Hello” your access point wouldn't send an H, an E, an L, an L and a O. It sends multiple characters for each one, just like you would on a static-filled radio or phone call. It will use its equivalent of the phonetic alphabet to send “Hotel”, “Echo”, “Lima”, “Lima”, “Oscar”.

    • That way, even if you didn’t hear the entire transmission, you are still likely to be able to know that “Hello” was being sent. The level of redundancy varies on signal strength and interference on the channel.

    • If the signal strength is high, the access point and receiver are able to use a complicated modulation scheme, and encode a lot of data.

    • If you think about our jump rope analogy from earlier, rather than just left and right, it can divide into 1/4s, 1/8ths, or further. It can also combine the direction of the modulation with strength, or phase of modulation.

    • The most complex modulation in Wi-Fi 6 is 1024-QAM, which has 1024 unique combinations of amplitude and phase. This results in high throughput, but requires a very strong wireless signal and minimal interference to work effectively.

  • As your wireless signal weakens, complex modulation can’t be understood. Both devices will step down to a less complex modulation scheme. This is why Wi-Fi slows down as you move away from the access point.

First In a Series: Wi-Fi 101

I plan on writing a whole series of posts about Wi-Fi fundamentals which will cover various topics about Wi-Fi, how to improve your home network, and related issues. If there is something you want me to cover, leave a comment below.

Footnotes
    1. The IEEE, an international standards body, sets the definitions of what Wi-Fi is. They’re the reason we have Wi-Fi standards with names like 802.11n, 802.11ac or 802.11ax. They’ve since renamed the major standards to Wi-Fi 1, 2, 3, 4, 5, and 6. With each generation, Wi-Fi gets better, and there are a lot of details to cover. I’ll cover that in a future post.

    1. Hertz did not realize the practical importance of his experiments. “It's of no use whatsoever. This is just an experiment that proves Maestro Maxwell was right—we just have these mysterious electromagnetic waves that we cannot see with the naked eye. But they are there.” When asked about the applications of his discoveries, Hertz replied, “Nothing, I guess.”You can pay your respects to this legend by always capitalizing the H in MHz and GHz.

    1. It takes about one second for a radio wave to travel from the Earth to the moon. It’s pretty amazing that over 50 years ago we had the technology to capture sound and images on the moon, turn them into electromagnetic waves, beam them back to Earth, and transmit them around the globe. I guess it’s pretty cool we put a human on the moon, too.

    1. If you keep adding energy to microwaves, you can end up in a unique part of the EM spectrum, visible light. Visible light’s wavelengths are measured in nanometers, and nanometers are really small: a human hair is around 75,000 nanometers wide. Visible light has a wavelength between 380 and 740 nanometers and a frequency between 405 and 790 THz (trillions of cycles per second). It’s hard to wrap your head around, but a lot of foundational physics is, too.

  1. Your eye is reading this page because your computer screen is sending out electromagnetic radiation in the visible light portion of the electromagnetic spectrum. Differences in the wavelength cause your eye to interpret different areas of the page as different colors. A whole lot of brain magic and pattern recognition lets you interpret those color variations as letters and words. If I did my job as a writer, there should also be some meaning behind those words. All from some waves shooting out of your screen. Physics is amazing, Wi-Fi isn't magic, and writing is telepathy.

Source: Reddit

V- LONGEST NETWORK CONNECTION IN THE UNIVERSE:

Every once in a while I go onto the Deep Space Network site to check on Voyager 1 and 2, and just to see what's going on in general. Currently the round-trip time to V1 is about 1.69 days with a data rate of 150 bits/second, although I've seen it as low as 6 bits/sec. V2 is a bit closer at a mere 11 billion miles or so. It's amazing to me that the entire space craft runs on 4 Watts. V1 and 2 have both departed the solar system.