VPC Flashcards
What are 3 IPs that are reserved for private IPs on a network?
1) 10.0.0.0 - 10.255.255.255
2) 172.16.0.0 - 172.31.255.255
3) 192.168.0.0 - 192.168.255.255
Do you have to create your own VPC when running a new EC2 instance?
No, all new EC2 instances can be added to AWS’s default VPC.
What is VPC peering?
Allows you to join two VPCs and instances behave as if they are part of the same network.
What is a VPC?
A logical data center in the cloud
What are the 5 main components of a VPC?
1) IGWs (or VPGs)
2) Route tables
3) Network Access Control Lists
4) Subnets (1 subnet == 1 AZ)
5) Security groups
Are Security groups stateful or stateless?
Security groups are stateful if you open one port (e.g. 22) then the outbound is allowed
What is a NACL?
Network Access Control List
Are NACL stateful or stateless?
Stateless. You must specify inbound and outbound IP address rules
Is transitive allowed for VPCs?
No, transitive peering is not allowed. Peering must be on a one to one basis, so separate connections must be made e.g. A and D VPC connection example
When a custom VPC is created what is created by default?
1) Route table
2) NACL
3) A security group (default)
What 2 things will not be created when a custom VPC is created?
1) Subnet
2) Default internet gateway
Are all assigned AZs the same for two independent AWS accounts?
No, they are not
How many IP addresses are reserved within your subnet?
5
What is the maximum number of internet gateways you can have in a VPC?
1
What does NAT stand for?
Network Address Translation
What is a NAT instance used for?
A NAT instance is used to allow access to the internet.
Where must NAT instances be situated?
They must be situated in a public subnet. There must be a route out of the private subnet to the NAT instance in order for this to work.
What is the most likely bottle neck of traffic in a NAT instance based network architecture?
The size of the NAT instance. Increase the instance size to reduce the bottle neck.
Are NAT instances in front or behind a security group?
Behind
How does a NAT gateway work?
An instance within your private subnet connects directly to a NAT gateway and the NAT gateway connect to the internet.