How to connect to EC2 in private VPC? - amazon-web-services

I create a VPC, and try to connect to a EC2 by connecting to AWS Ubuntu.
But when I go to the page of connecting, it showed me this
The instance does not have a public IPv4 address
To connect using the EC2 Instance Connect browser-based client, the instance must have a public IPv4 address.
What I've tried
In EC2 Panel > Action > Networks > Manage IP Address > Ipv4 Addresses > Assign New IP Address(only available for priate IP Address, but I couldn't do anything in section of pubilc IP Address)

Go to the EC2 dashboard, on the left panel, open Network & Security -> Elastic IPs
Allocate an elastic IP, and click Actions dropdown. Click Associate Elastic IP address.
You can connect the elastic IP to your instance or Network interfaces of the instance.

Follow the AWS link instruction.
https://aws.amazon.com/premiumsupport/knowledge-center/ec2-associate-static-public-ip/

First, do you mean Private Subnet?
Also ensure port 22 is open from correct ip. Private EC2 can't be accessed from public internet.
To connect with EC2 in private subnet you need a bastion host & NAT gateway attached.
Refer this link for more info.

Related

SSH using Public IP over the VPN

I have an EC2 instance launched in Private Subnet.
I have also launched an AWS Client VPN and did all of the configurations and I am able to connect to my EC2 instance via Private IP.
There is a service running on Port 25, I am able to telnet to that as well using the Private IP.
But when I try to do telnet using the Public IP of the Instance, I am not able to do so. Also, I am not able to ssh into Instance when I am connected to VPN using the Public IP.
How can I ssh into my EC2 Instance using Public IP when I am connected to VPN?
I don't want to add my machine's Public IP in the Security Group and then do the SSH.
If an Amazon EC2 instance is in a private subnet (defined as having a Route Table that does not point to an Internet Gateway), then the instance will not be reachable via public IP address.
Public IP addresses are routed via the Internet Gateway. Since there is no route between the Internet Gateway and the instance, it cannot be reached via the public IP address.

Is there any AWS setup that can associate a fixed IP to a domain?

I need to create a security group that allows traffic between an EC2 instance and a certain domain.
Problem is, the IP associated to a domain can change (or there can be multiple IPs), so I can't create a security group.
Is there any AWS service/setup to have the EC2 instance connect to a fixed IP, that then connects to the given domain?
Is there any AWS service/setup to have the EC2 instance connect to a fixed IP
You can associate Elastic IP address with your instance:
An Elastic IP address is a public IPv4 address, which is reachable from the internet. If your instance does not have a public IPv4 address, you can associate an Elastic IP address with your instance to enable communication with the internet. For example, this allows you to connect to your instance from your local computer.
What's more, EIP is free as long as:
The Elastic IP address is associated with an EC2 instance.
The instance associated with the Elastic IP address is running.
The instance has only one Elastic IP address attached to it.
Having the EIP you can associate it with a domain through an A record.
Yes you can assign a fix ip address to ec2 instance using "Elastic ip"
To allocate an Elastic IP and associate it with an Ec2 instance follow below steps:
Go to ec2 dashboard click on elastic IPS under Network & security then click on Allocate Elastic IP address and click Allocate
Once an IP is allocated you need to associate it with the EC2 Instance
Click ip address and go to Actions and choose Associate Elastic IP address.
In the Resource type choose Instance and and choose the instance from the dropdown on the Instance field and click Associate.

How can i connect to a EC2 machine which is within a VPC being ELB

I am trying my hands on VPC and ELB.
my question is .
when we create a EC2 instance in default VPC we have public ip attached to it and we can ssh into it.
BUT
When i create an instance with in a VPC there i don't see any public ip to ssh into .
so where can i find the public ip of the instance.so that i can ssh into
Also note what happens when: instance in a part of security group attached to ELB.
setting an elastic ip to the instance is one part . What if auto scaling spins up another instance what happens then ?
if i need to deploy into the EC2 . how would i do it? how do i access the public ip
When you create an instance under public subnet it does not mean the instance will have public access automatically, you need to enable public IP during launch process if you want to do that after:
Select EC2 instance> Actions>Networking> Manage Ip Addresses. Then use the option "To add or edit an IPv4 public IP Allocate an Elastic IP to this instance or network interface".
Create an elastic IP
Navigate to Elastic IP address link> click Associate IP
Select the instance to associate IP and save.
Now you will have EC2 instance with public IP without restarting/deleting EC2 instance.

Why I can't access via SSH to my AWS Instance after rebooting?

I can't access to my instance via SSH after rebooting.
Also if Instance Status is running.
How can I fix it?
The public ip address of the EC2 instance will change after the reboot if the instance do not have an elastic ip address assigned. You can check the new public ip address on the EC2 console. If you attach an Elastic ip address, it will not change after reboot.
To determine your instance's public IPv4 addresses using the console
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Instances.
Select your instance. In the details pane, get the public IP address from the IPv4 Public IP field, and get the external DNS hostname from the Public DNS (IPv4) field.
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-instance-addressing.html
Here is how you can attach an elastic ip address.
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/elastic-ip-addresses-eip.html

Connect to EC2 instance with a private IP address via a VPN

I've created a VPC with IPv4 CIDR 172.16.0.0/16, next I've created three subnets:
subnet_1 172.16.0.0/20
subnet_2 172.16.16.0/20
subnet_3 172.16.32.0/20
Next I created an Internet Gateway attached to the VPC.
At this point I've created an EC2 instance and I attached to it an Elastic IP. On this instance I have installed an OpenVPN access server.
I then created a second EC2 instance that only has a private IP address. In my mind I thought that once connected via VPN I should able to ssh into the second EC2 instance with a private IP, but I'm not able to connect. What might I have done wrong?
EDIT: I edit the post with some additional information
This is how I configured my VPC
My subnets attached to the VPC
The internet gateway attached to VPC
This is my EC2 instance with OpenVpn access server, with his Elastic Ip so that I can access from my browser
Inbound rules for security group of vpn instance
And the outbund rules
The second and private instance (the instance to which I want to connect via VPN)
Inbound rules
And outbund rules
In OpenVpn access server I do this configurations
And when I connect to the VPN I receive this address 172.16.128.2 (for example)