Introduction to Compute & Networking

Question 1

EBS volumes exist outside of _ and replicated within _ for high durability.

Answer 1

1. EC2
2. Availability Zone

You can attach EBS volume to a single instance at a time within same AZ.

Question 2

When you launch an EC2 instance, a root _ volume is typically created by default. This volume contains the operating system.

Answer 2

Root EBS Volume

By default, the root volume is deleted when the instance is terminated, but you can change this behavior. Additional data volumes attached to an instance are not deleted by default upon instance termination.

RV is deleted when instance is terminated but u can change this behavior

Question 3

Cross-AZ or cross-Region durability of an EBS volume is possible through _

Answer 3

snapshots

You can create new EBS volumes from snapshots.

Question 4

AWS service for automating the creation, retention, and deletion of EBS snapshots

Answer 4

Amazon Data Lifecycle Manager (DLM)

Question 5

Incremental EBS snapshots are stored in _.

Answer 5

Amazon Simple Storage Service (Amazon S3)

they are stored in AWS’s internal S3 infrastructure, managed by the EBS service, and not in an S3 bucket.

When you restore a volume from a snapshot, AWS reconstructs the full volume based on all the necessary incremental snapshots.

Question 6

The simplest way to reduce boot/launch time of new instances in an Auto Scaling Group is through

Answer 6

Amazon Machine Image (AMI)

Question 7

_ provides the template for the OS and applications on the root volume of EC2 instance.

Answer 7

AMI

AMIs also provide configuration of additional volumes to mount when an instance launches.

Question 8

if you want your EC2 instance to be reachable from the public internet without having its own public IP, the most common and robust approach is to place it behind a Public _. If you primarily need your instance to initiate connections to the public internet (and not receive unsolicited inbound connections), then a _ is the way to go.

Answer 8

1. Load Balancer (ALB or NLB)
2. NAT Gateway

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Question 9

Unlike public dynamic IP, _ is tied to the AWS account and not to the EC2 instance.

Answer 9

Elastic IP

Question 10

Unlike the primary _, you can detach a secondary _ from one EC2 instance and later attach it to another.

Answer 10

Elastic Network Interface (ENI)

You can attach multiple network interfaces (ENIs) to an EC2 instance

Question 11

_ protect traffic entering and exiting an instance’s network interface. They act as a stateful firewall.

Answer 11

Security groups

To make network connections to your instance, you must set security group rules to allow the connection.

Question 12

_ EC2 instances provide remote access through Secure Shell (SSH), and _ EC2 instances provide remote access through the Remote Desktop Protocol (RDP)

Answer 12

1. Amazon Linux
2. Amazon Windows

Question 13

Default user for Amazon Linux instances is _.
Default user for Amazon Ubuntu instances is _.
Default user for Amazon CentOS instances is _.
Default user for Amazon Windows instances is _.

Answer 13

1. ec2-user
2. ubuntu
3. centos
4. Administrator

You’ll use it while connecting (e.g., ec2-user@instance-public-ip)

Question 14

AWS allows you to configure SSH key access at instance creation time by associating an _ with the default login user.

Answer 14

EC2 key pair

When you try to connect via SSH, your local SSH client uses your private key to prove your identity to the EC2 instance, which has the corresponding public key. It’s like a highly secure digital handshake.

Question 15

AWS doesn’t create a new key pair for each instance launched by an ASG in the traditional sense (where you download a new .pem file). Instead, you “pre-configure” the key pair that new instances should use as part of the ASG’s setup through _.

Answer 15

Launch Template (previously Launch Configuration)

When you create a Launch Template, you specify the name of an existing key pair that you have already created and uploaded to AWS.

For any instance launched using this template, place the public key associated with this name on the instance.” The private key, which you hold, is then used by you to connect to those instances. The best practice is to keep that private key file (.pem) on your local machine, protected by a strong passphrase, and with strict file permissions.

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Question 16

_ is a feature of AWS Systems Manager Service that provides a browser-based interface to your EC2 instance, allowing you to log in without requiring to maintain SSH key-pairs or requiring to open inbound port 22 by modifying inbound rules of Security Group.

Answer 16

Sessions Manager

Question 17

_ provides a secure, temporary (time-bound) access to your EC2 instance using SSH, without permanent keys.

Answer 17

EC2 Instance Connect

It simplifies key management by allowing you to push a temporary SSH public key to the instance’s metadata. So, no need to manage permanent keys.