Networking

Question 1

Amazon Virtual Private Cloud (VPC)

Answer 1

Logically isolated section of AWS cloud where you can launch AWS resources in a virtual network that you define
Resources can be public or private (no internet access)
Subnets: ranges of IP addresses in VPC
Public subnet: aka the cashier in a coffee shop
Private subnet: aka the barista, who should not interact with customers and only focuses on making coffee

Question 2

Public gateway

Answer 2

To allow public traffic from the internet to access your vpc, you must attach an internet gateway to the vpc

Internet gateway is a connection between a vpc and the internet

Question 3

Private gateway

Answer 3

Virtual private gateway
Allows protected internet traffic to enter into the vpc if it comes from an approved network
Create a vpn connection between a private network and your vpc

Question 4

AWS Direct Connect

Answer 4

Dedicated private connection from your data center to AWS
Helps sidestep bandwidth issues

Question 5

Public subnet

Answer 5

contains resources that need to be accessible by the public, ex online store’s website

Question 6

Private subnet

Answer 6

contains resources that should be accessible only through your private network, ex database with personal info

Question 7

Network Traffic Flow in a VPC

Answer 7

When customer requests data from an app in the cloud, the request is sent as a packet - a unit of data sent over the internet or network

It enters into a vpc through an internet gateway
Permissions get checked to indicate who sent the packet and how the packet is trying to communicate with the resources in a subnet

Question 8

Network access control list

Answer 8

vpc component that checks packet permissions
Virtual firewall that controls inbound and outbound traffic at the subnet level
By default, all inbound and outbound traffic is allowed, but you can add your own rules
For custom network ACLs, all traffic is denied until you add rules for what traffic to allow

Question 9

Stateless Packet filtering

Answer 9

Remember nothing and check packets that cross the subnet border each way: inbound and outbound

Question 10

Security groups

Answer 10

A virtual firewall that controls inbound and outbound traffic for an EC2 instance
Stateful packet filtering: remember previous decisions made for incoming packets
Security groups deny all inbound traffic by default, must add custom rules to allow traffic

Question 11

Amazon Route 53

Answer 11

translates websites into IP addresses
Connects user requests to infrastructure running in AWS
Can route users to infrastructure outside of AWS
Can also manage DNS records for domain names
You can register new domain names, and transfer records for existing domain names