AWS Fundamentals Flashcards
What is the difference between a private and a public service
The networking only
Where does a private service run
Within a VPC
Where does a public service run
Withing the public internet zone
When can on-prem access VPCs
With a VPN or Direct Connect, or if it has an internet gateway
Is EC2 public or private
Private, but you can attach a public IP`
What does Route 53 allow you to do
Register domains and host zones on managed nameservers
What kind of resilience does route 53 have
Global resilience, it has a single db
What is an NS record type
Name server
What do A records and AAAA records do
They map host names to IP addresses
What is the difference between A and AAAA record
A: maps to IPv4 address, AAAA maps to IPv6 address
What do CNAME records do
They allow you to create the equivalent of DNS shortcuts, or host-to-host. They can only point to names
What can CNAME records point to
Name only, it cannot point to IP
What do MX records do
They are used for email
How many default VPCs do you have per region
Only one
How many custom VPCs can you have per region
Many
What is a difference between the default VPC and custom ones
The default one is a lot less flexible
What is a VPC CIDR
The range of addresses allocated to the VPC
How many IP ranges can a VPC get
The default VPC only gets one, custom VPCs can have many
What type of resilience do VPCs have
Regional resilience
What is the default VPC address range
172.31.0.0/16
How many subnets per AZ does the default VPC have
One
What port is used for RDP
3389
What port is used for SSH
22
What is the unit of billing for EC2
Per second
What arethe three possible states of an EC2 instance
Running, Stopped, Terminated
What do you get charged for with a stopped instance
Disk
What does AMI stand for
Amazon Machine Instance
What kind of resilience does S3 have
Regional resilience
What is the maximum size of an object in an S3 bucket
5 TB
What is a restriction for bucket names
They must be globally unique
When does data leave the region an S3 bucket is in
It never does unless configured to do so
What is the structure of S3 bucket
Flat, no folders but prefixes so the UI acts lik eit does
What are all the restrictions for an S3 bucket name
- Name must be globally unique
- 3-63 chars, all lowercase, no underscores
- Starts with a lowercase letter or a number
- Cannot be IP formatted
How many S3 buckets can an account have
100 is a soft limit, but you can have more with support requests. 1000 is a hard limit
How many objects can you have per bucket
Unlimited
What are the key and value in an S3 bucket
Key is the name of the object, Value is the data
What kind of storage is S3
Object, not file or block
Can you mount an S3 bucket
No, use EBS if you want to mount (EBS is block storage)
What is the only mandatory part of a CloudFormation template
The Resources section
What is the restriction concerning AWSTemplateFormatVersion
If you have one and a description, the description must come right after
When is the CloudFormation stack created
When you take a template and tell CloudFormation to do something with it
What is High Availability
Minimize any outages
What is Fault-Tolerance
Operate through faults, it is more complex and expensive
What is Disaster Recovery
What we do when HA and FT don’t work
What Permissions options does and AMI have
Public Access, Owner only, Specific AWS Accounts
What is not stored in an AMI
- Instance settings
- Network settings
What is stored in an AMI
- Boot volume
- Data volume
- AMI Permissions
- Block Device Mapping
EC2 is an example of which service model
IaaS
Where is an AWS Public Service located
AWS Public zone
Who can connect to an AWS Public service
Anyone, but permissions are required to access the service
Where is an AWS Private Service located
VPC
Where is an AWS Private Service accessible from
- From the VPC it is located in
- From other VPCs or on-prm networks as long as private networking is configured
What kind of service is S3
Public
What kind of storage system is S3
Object storage system
What amount of data can S3 buckets store
Unlimited
What is a CloudFormation Logical Resource
A resource defined in a CloudFormation Template
What is a CloudFormation Physical resource
A physical resource created by creating a CloudFormation stack
What is a simple definition of High Availability
A system which maximises uptime
What is a simple definition of a Fault Tolerant system
A system which allows failure, and can continue operating without disruption
How many DNS root servers exist
13
Who manages the DNS Root servers
12 large organizations
Who manages the DNS Root Zone
IANA
Which DNS Record Type converts a HOST into an IPv4 Address
A
Which DNS Record type is how the root zone delegates control of .org to the .org registry
NS
Which type of organisation maintains the zones for a TLD (e.g. .ORG)
Registry
Which type of organisation has relationships with the .org TLD zone manager allowing domain registration?
Registrar
How many subnets are in a default VPC
Equal to the number of AZ in the region the VPC is located in
What is the IP CIDR or a default VPC
172.31.0.0/16
