Unable to connect to amazon EC2 instance via PuTTY

Question

I created a new instance of Amazon EC2 in Amazon Web Services (AWS) by referring to the documentation. I even added a SSH rule like this:

Port: 22  
Type: SSH  
Source: <My IP address>/32

I downloaded the .pem file, converted it into .ppk file by using PuTTYGEN. Then I added host name in PuTTY like this:

ec2-user@<public_DNS>

I selected default settings, added that .ppk file to PuTTY, logged in and I got this error:

Even trouble shooting link didn't help me.
I'm also getting this error in system logs:

How can I connect to my Amazon EC2 instance via PuTTY?

Solution 1

Things to check when trying to connect to an Amazon EC2 instance:

• Security Group: Make sure the security group allows inbound access on the desired ports (eg 80, 22) for the appropriate IP address range (eg 0.0.0.0/0). This solves the majority of problems.
• Public IP Address: Check that you're using the correct Public IP address for the instance. If the instance is stopped and started, it might receive a new Public IP address (depending on how it has been configured).
• VPC Configuration: Accessing an EC2 instance that is launched inside a Virtual Private Cloud (VPC) requires:
  • An Internet Gateway
  • A routing table connecting the subnet to the Internet Gateway
  • NACLs (Network ACLS) that permit through-traffic

If you are able to launch and connect to another instance in the same subnet, then the VPC configuration would appear to be correct.

The other thing to check would be the actual configuration of the operating system on the instance itself. Some software may be affecting the configuration so that the web server / ssh daemon is not working correctly. Of course, that is hard to determine without connecting to the instance.

If you are launching from a standard Amazon Linux AMI, ssh would work correctly anytime. The web server (port 80) would require installation and configuration of software on the instance, which is your responsibility to maintain.

Solution 2

Ajay,

Try this. Go to your VPC dashboard. Click on Network ACLs - on the associated acl, update your Inbound Rules to allow SSH access on port22.

Comments

[helloV]

Is it Ubuntu Linux or some other distro?

[Volkan Paksoy]

Do you any response when you try telnet like this: telnet 52.27.219.7 22 ?

[Ajay Kulkarni]

@helloV: it is amazon linux HMV(Fedora)

[Ajay Kulkarni]

@VolkanPaksoy: I got this error: Connecting To 52.27.219.7...Could not open connection to the host, on port 23: Connect failed. I deleted my old instance and created new instance with the public ip 52.27.219.7.

[Volkan Paksoy]

@AjayKulkarni: Port has to be 22, not 23. If still it doesn't work try allowing access from everywhere 0.0.0.0/32 temporarily. If it works then it has something to do with your IP. Make sure you still have the same external IP

[Ajay Kulkarni]

I tried telnet 54.68.184.49 22 where 22 is the port number. I got this error: Connecting To 54.68.184.49...Could not open connection to the host, on port 22: Connect failed. I set ip to 0.0.0.0/32, and telnet didn't connect to the public ip. I'm updating the question, wait

[erik258]

0.0.0.0/32 is just the ip 0.0.0.0 - that's never going to be the source of any traffic. 0.0.0.0/0 is any IP. Better to put in your IP because if SSH is open to all IPs you will have folks attempting to use it to access your system.

[John Rotenstein]

Ajay, is your instance in a public subnet? If not, it would be unable to access the Internet, which could explain the failed cloud-init configuration and your inability to login. Look at the configuration of the subnet and ensure that it is routing through an Internet Gateway.

[Abhi]

AWS Help Desk Answet: Network connectivity to an EC2 instance is not enabled by default. You need to make some configuration changes in your VPC in the AWS management console. aws.amazon.com/premiumsupport/knowledge-center/…

[stdunbar]

What is "my ip"? This might help but some details would be good.

[kon19]

@stdunbar In the INBOUND RULES Add a role as a SSH If you don't have yet and make the SOURCE from ANYWHERE then save it and try to log in from the CLI. Then go back and put your own IP address or an custom IP for security reasons. MyIP means your current IP. Look at the screenshot i.ibb.co/b7w4BBk/889.jpg