EC2

Question 1

What are the capabilities of EC2

Answer 1

Renting Vm’s (EC2)
Storing data on virtual drives (EBS)
Distributing Load(ELB)
Scaling services (ASG)

Question 2

How is traffic allowed in/out of EC2 machines?

Answer 2

Security Groups

Question 3

What acts as a firewall for EC2 instances?

Answer 3

Security Groups

Question 4

What do Security Groups regulate?

Answer 4

Access to ports
Authroized IP ranges
Control of inbound/outbound network

Question 5

Can Security Groups be attached to multiple instances?

Answer 5

Yes

Question 6

Is a Security Groups locked down to a region/VPC combo?

Answer 6

Yes

Question 7

Where does the Security Group live?

Answer 7

Outside the EC2 instance

Question 8

How many Security Groups should maintain SSH Access?

Answer 8

One

Question 9

If application isnt accessbible(timed out) what’s wrong?

Answer 9

Security Groups issue

Question 10

If application gives a “connection refused” error, what’s wrong?

Answer 10

Application error or its not launched.

Question 11

What are the inbound/outbound traffic defaults

Answer 11

Inbound is blocked/outbound is authorized.

Question 12

What are the fundamentals of a public IP?

Answer 12

Machine can be identified on the internet
IP is unique
Can be geo-located

Question 13

What are the fundamentals of a private IP?

Answer 13

Identified on private network only.

IP unique on private network.

Question 14

How do machines connect to internet(WWW)?

Answer 14

internet Gateways(Proxies)

Question 15

Can you use any range for private IPs?

Answer 15

No, only specific range is used.

Question 16

What is an Elastic IP?

Answer 16

Fixed public IP.

Question 17

How many instances can an Elastic IP attach to?

Answer 17

One instance at a time.

Question 18

What happens when you stop, then start an instance?

Answer 18

The IP changes

Question 19

How many Elastic IP’s can you have?

Answer 19

5 (you can ask for more)

Question 20

What should you avoid using Elastic IPs?

Answer 20

Reflect poor architectural decisions

Question 21

What should you do instead of using Elastic IPs?

Answer 21

Use random public IP and register a DNS name to it.

Or, use a Load Balancer and dont use a public IP

Question 22

By default, your EC2 machine comes with what?

Answer 22

• A private IP for the internal AWS Network

* A public IP, for the WWW.

Question 23

When we are doing SSH into our EC2 machines what can we do, what cant we?

Answer 23

• We can’t use a pr ivate IP, because we are not in the same networ k
• We can only use the public IP.