AWS - Create VPC, Subnet mask, private and public EC2 instances creation

Step by step Guide to create VPC, subnet mask and creating EC2 instances to public and private subnet.
and connecting private instances to internet.

 

 What is VPC
- VPC is a logical boundary to allow communication witin the subnet.
- You can call VPC as your company building.
- Subnet is kind of datacenter with server, network connectivity.
- Public Subnet can access to internet since it is mapped with public IP
- Private subnet is not mapped with public IP so can't directly communicate outside subnet.


A. Create VPC        # note: mask bit can not be less than 16.
1. Go to AWS Dashboard
2. Search for VPC -> Your VPC
3. Create VPC
   Name: DC-VPC     IPv4: 192.169.0.0/16
4. Click on create

B. Create Public Subnet
5. Click on Subnets from VPC Dashboard
   Name: DC-PUB-Subnet    VPC: DC-VPC
   VPC CIDR: 192.168.0.0/16    - Associated
   IPv4 CIDR: 192.168.10.0/24
6. Click on Yes Create

C. Create Private Subnet
7. Now, you on VPC Dashboard under subnets
8. Click on create subnet
   Name: DC-PVT-Subnet    VPC: DC-VPC
   VPC CIDR: 192.168.0.0/16
   IPv4 CIDR Block: 192.168.20.0/24
9. Click on Yes Create

D. Create Internet Gateway
10. Now, click on Internet Gateways
11. Click on create internet Gateway
    Name Tag: DC-IGW
12. Click on Yes Create
13. Click on DC-IGW and click on Attach to VPC
14. Select DC-VPC and click on Yes Attach

E. Create Public Route table
   - Here you will associate public subnet with public route
   - And
15. Click on Route Tables
16. Click on Create Route Table
    Name: DC-Pub-route    VPC: DC-VPC
17, Click on Yes create.
18. Click on Route Tables you just created
19. Click on Subnet Associations and click on Edit
20. Select the DC-Public-Subnet and click on SAVE.
21. Click on Routes and click on Add another route
    Destination: 0.0.0.0/0    Target: DC-IGW
22. Click on Save

23. Again click on Create route table
    Name: DC-Pvt-route    VPC: DC-VPC
24. Click on Yes Create
25. Select the private route you just created and click on Subnet Associations Tab
26. Click on Edit and select DC-Pvt-Subnet
27. Click on Save.
27. Click on Router

F. Create AWS instances on private and public subnet
28. Launch EC2 instances on pub subnet (internet access) and private subnet.
    - To login to private subnet machine, first login to pub machine and from there login to private

G. How to allow internet access to private subnet
29. Create a NAT Gateway in public subnet
30. Go to private route table and add NAT-GW rule to allow private machines to have internet.


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How to connect to private VM in AWS ?

1. Create VM on Private and Public Subnet.
2. Login to public VM and create a directory with full permission.
3. Copy the keys there.
   $ ssh -i "mykey.pem" ec2-user@pub-IP_of-inst
   # mkdir /mykeys; chmod 777 /mykeys
   # exit

4. Copy private key to public VM
   $ scp -i mykey.pem <my-keyfile> ec2-user@pub-inst-IP:/mykeys
   $ scp -i mykey.pem mykey.pem ec2-user@55.230.15.34:/mykeys

5. Now, login to your public VM again. Go to /mykeys.
6. Now, initiate a ssh connection to private VM.
$ cd /zkeys
$ ssh   -i  <key*.pem>  ec2-user@<PVT_IP>


Create Nat Instance
launch in  public subnet