VPC Flashcards
What is a VPC?
Virtual Private Cloud
It is a virtual network dedicated to your AWS account.
What is a Region?
AWS Regions are separate geographic areas.AWS Regions consist of multiple, physically separated and isolated Availability Zones that are connected with low latency, high throughput, highly redundant networking.
What is an Availability Zone?
They are distinct locations within an AWS Region that are engineered to be isolated from failures in other Availability Zones. They provide inexpensive, low-latency network connectivity to other Availability Zones in the same AWS Region.
What is an Edge Network?
They are a content delivery network with locations outside AWS data centers, which means they are not inside a region/availability zones. An example is of an aws service that live in an edge network is cloudfront.
What are the minimum and maximum CIDR blocks available for use in AWS?
/28 minimum
/16 maximum
What is the default VPC CIDR address range?
172.31.0.0/16
Can subnets extend from one VPC in one availability zone to another VPC in another availability zone?
No
What are the private ipv4 address ranges?
10.0.0.0 - 10.255.255.255 /8
172.16.0.0 - 172.31.255.255 /12
192.168.0.0 - 192.168.255.255 /16
If you allocate a new subnet 10.0.0.0/24 within a VPC, how many addresses are available?
Only 250 IPs will be available because AWS reserves 5 IPs.
10.0.0.0 - Network address
10.0.0.1 - VPC router (gateway)
10.0.0.2 - Route 53 (amazon provided DNS)
10.0.0.3 - AWS future use
10.0.0.255 - Typically a broadcast address, but AWS does not allow broadcasts within a VPC, so this is just reserved.
If you restart an EC2 instance, and it is assigned both a private and public ip addresss, would the instance retain it’s public ip address?
No, by default, the EC2 instance will not retain the previous public ip before the restart. AWS will assign it a new public ip. Your private ip will remain the same before the restart.
What are the three types of ip addresses within a VPC?
1) Private IP
2) Public IP
3) Elastic IP
What two types of IP addresses can communicate on the internet?
1) Public IP
2) Elastic IP
If you terminate an EC2 instance and it was using an Elastic IP, will this also be deleted?
No, the Elastic IP is still tied to your AWS account, and you will be billed for it.
An EC2 instance using an Elastic IP was terminated, can we reuse this IP?
Since the Elastic IP is not attached to an EC2 instance, this can be reused on the new EC2 instance.
If you assign an EC2 instance an IPv6 address and restart the EC2 instance, will it lose that ip?
Since IPv6 is globally unique, you will not lose the ip when restart the EC2 instance; you will retain this ip.