I had a running instance, and then I became unable to connect to it via http(80) and ssh(22). I tried to reboot the instance, but nothing went up. This has happened to me twice in the past month.
Why does it happen? Can I do anything to fix and/or prevent it from happening?
If I launch a new instance in same region, and it works.
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.
Related
My problem is that I want to run an application on an AWS EC2 instance on port 3000. I then want to be able to access it from the internet using http:/PUBLIC_IP:3000. The problem is that when I am running the application on the EC2 instance, it runs on the private IP - and therefore I cant access it from the internet. How would I make sure that the app will run on the public ip, or how would I set it up, so I can access the application over the internet?
I tried to find a solution online, but some hours later I find myself in here.
Thank you for your help. It was very helpful in debugging the error. It turned out that the security group of the EC2 instance was not allowing traffic on port 3000 so I had to add that - and then it worked.
I furthermore had trouble putting it behind a Load Balancer. The solution to that was that it was a webpack application and in .webpack there is a configuration file where you can add e.g., allowedHosts: [.amazonaws.com].
If I put the "IPv4 Public IP" of my EC2 instance in the browsers address shouldnt it connect and return an error message instead of just giving time out ?
So, it sounds like you are attempting to connect to the instance via SSH.
Things to check:
The Security Group associated with the instance needs to have port 22 open to either your Public IP address, or to 0.0.0.0/0 (which is not a good security practice)
You are on a network that is not blocking SSH traffic. Some corporate network prohibit such access (so try it from home).
The instance is running an SSH server. This is standard on Linux distributions, such as the Amazon Linux AMI. (Believe it or not, some people wonder why they can't SSH to a Windows instance.)
You should be trying to connect to a public IP address associated with the instance
The instance needs to be in a Public Subnet (which means the Route Table associated with the Subnet is pointing 0.0.0.0/0 traffic to an Internet Gateway). If you are using the Default VPC, then this is done for you.
You have the private half of the keypair that was nominated when the instance was launched. If you are using an Amazon Linux instance, the private half of the keypair would have been automatically copied to: /home/ec2-user/.ssh/authorized_keys
The fact that your connection is timing-out, as opposed to receiving an error message, most likely makes it an incorrectly configured Security Group. (Trust me, it's almost always the Security Group!)
I am trying to set up my JMeter master/slave set up on AWS EC2 instances using windows. Out of the box integration didn't work (connection refused errors) and after some investigation I got to know that RMI communication only works if the machines are on same subnet (is this true?). I found this great article and I tried to follow it as is on windows (tried running ssh port forward tunneling via cygwin) but not have any luck. So I was hoping if someone already done this with Windows and can share their experience.
Out of the box integration didn't work (connection refused errors) and
after some investigation I got to know that RMI communication only
works if the machines are on same subnet (is this true?)
It is not necessary. Even if the machines are in a different subnet and addressable via the network, RMI should work. Here make sure the Security Groups and NACLs are properly set so that both EC2 instances can communicate with each other via the network.
You can check whether you can ping(For this you need to enable ICMP in your Security Groups and also make sure other needed ports are opened for RMI) from one EC2 instance to another. If the servers can communicate with each other, then you need to troubleshoot internal firewall configuration in windows EC2 instances.
We have used https://testable.io/ AMI's from the marketplace. It takes care of all configuration and just needs to worry only about testing and the results.
https://aws.amazon.com/marketplace/pp/B073JNTVKP
All our endpoints are secured to certain IP-ranges from testable.io. If you have internal, still you need to setup those security settings.
Hope it helps.
I have a domain www.rentcars.sg which is pointed to the right DNS server and verified by someone else and is working correctly: https://forums.aws.amazon.com/message.jspa?messageID=362885#362885
However, even though I setuped the domain correctly on the server with IIS, it's not working correctly.
Can anyone point me to the right direction? Is there any additional setup I need to make to get it working?
Server IP : 23.23.129.247
Using the internal IP, it works but not with the server ip with port/url.
I am not sure if I understand your problem, but my approach would be:
Allocating EC2 Elastic IP Address.
Associating such an address with your running EC2 instance.
Pointing your domain name to this IP address.
Adding inbound TCP rule for all IP sources (0.0.0.0/0) in Security Group settings belonging to your EC2 instance.
Keep in mind that windows instances in AWS come with the software (windows) firewall enabled by default. Make sure that you have the correct firewall policies in place in the software firewall as well as the security group.
I have a free Amazon EC2 instance. And I installed Apache web server on it. I have the DNS record for my domain point to the ip for the EC2 instance. I can not access to my website. Then I looked up and allow the http inbound. But I still failed to access my web? What might be the reason. Anybody gives me a clue?
Go to the AWS management console and look at the Security Group the instance is in. Then make sure you have the port open that you are trying to connect to (most likely 80). To open it to the world set the ip range to 0.0.0.0/0 and to open it to a specific ip (like only your house) set it to xxx.xxx.xxx.xxx/32.
That is almost always the reason people have problems connecting when they are new to AWS. I wrote this post, which should help get you setup.