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Can't connect to the web server on an EC2 instance
Posted on: Jul 3, 2010 8:31 PM
The instance a windows 2008 server. I download Tomcat made sure it works by remote connecting to it.
1. The URL 'http://localhost:8080' works with a browser inside the instance.
2. I also made sure that there are the following two entries added to the security group associated with the instance.
HTTP tcp 80 80 0.0.0.0/0
- tcp 8080 8080 0.0.0.0/0
3. I then try 'http://ec2-184-73-15-234.compute-1.amazonaws.com:8080' on my desktop, but always get timed out.
I tried to change the Tomcat http port to 80 and follow the same steps and still fails to get the page.
What's the issue here?
Replies: 13 Pages: 1 - Last Post: Apr 21, 2017 9:17 AM by: ML
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 3, 2010 9:45 PM
Hi biwood64,
It looks like you've properly configured your security groups. You may also want to verify that there is no local firewall running on your instance:
$ sudo /sbin/iptables -L -n
Or if there is a firewall, that it permits traffic on tcp:8080 from external IP addresses.
Additionally, you might check to see if your Tomcat is listening on the public interface of your instance. You can do this by running:
$ netstat -l -n grep 8080
and see if your Tomcat is listening on 0.0.0.0:8080 (as opposed to something like 127.0.0.1:8080). If not, you may want to reinvestigate your Tomcat configuration.
Hope this helps!
-Jason
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 4, 2010 2:26 PM
Hi Jason,
Thanks for the response!
Regarding your suggestion about checking if there is a local firewall running on my instance, I thought there is always a firewall running on the local instance and the security group that I associate with the instance provides permission rules for the instance. Am I wrong?
I suppose the iptables command is for linux/unix, but my instance is a windows 2008 server. Is there an equivalent command for the windows server?
I did run the netstat command 'netstat -a -n' on windows and saw the 0.0.0.0:8080 and 0.0.0.0:80 entries.
Is it possible for you or an amazon staff to log on to my instance and check what the issue is? I am evaluating using EC2 as a solution for my start-up company, but I am really stuck. I don't know what I can do to fix the issue.
Regards,
Biwood
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 5, 2010 2:10 AM
Hi there
Is there a Windows Firewall blocking this service? I have tried to open a connection to port 8080 and receive a connection refused error message.
Unfortunately, for security reasons, Amazon staff do not have the ability to log into instances to assist with troubleshooting on any operating system / application related issues.
I'd definitely recommend that you log into the instance and see if your Windows Firewall is configured correctly.
Many thanks
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 5, 2010 9:20 AM
Hi CallumH,
I understand that chances are there are some kind of configuration issues. The problem is that I don't know how to figure out what the issue is. Would you please provide me the list of steps to check what might be wrong?
The only configuration that I added is to allow port 8080 and port 80 for HTTP access with the security group and that seemed to be pretty straightforward. Here are the output using 'ec2-describe-group'.
C:homeawsec2-api-tools-1.3-51254bin>ec2-describe-group
GROUP 424264346979 webtest web test
PERMISSION 424264346979 webtest ALLOWS tcp 80 80 FROM CIDR 0.0.0.0/0
PERMISSION 424264346979 webtest ALLOWS tcp 3389 3389 FROM CIDR 0.0.0.0/0
PERMISSION 424264346979 webtest ALLOWS tcp 8080 8080 FROM CIDR 0.0.0.0/0
GROUP 424264346979 default default group
PERMISSION 424264346979 default ALLOWS all FROM USER 424264346979
PERMISSION 424264346979 default ALLOWS tcp 80 80 FROM CIDR 0.0.0.0/0
PERMISSION 424264346979 default ALLOWS tcp 3389 3389 FROM CIDR 0.0.0.0/0
PERMISSION 424264346979 default ALLOWS tcp 8080 8080 FROM CIDR 0.0.0.0/0
Thanks,
Biwood64
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 5, 2010 9:37 AM
BTW, I restarted the instance and reconfigured Tomcat to listen to port 80. Everything else stays the same. Here is the URL that I use from my desktop at home 'http://ec2-174-129-122-184.compute-1.amazonaws.com'. I still get timed out with it.
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 6, 2010 10:15 AM
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 6, 2010 10:31 AM
biwood64,
i just tried a telnet to port 80 at ec2-174-129-122-184.compute-1.amazonaws.com and got no connection. This leads me to believe that there is no connection to port 80 to your instance.
You say that you added the appropriate permissions to both group webtest as well as default. Can you double check this?
Also, can you print out the security groups launched with your instance? You can simply show the output of ec2-describe-instances
My hunch is that your instance was not launched with the appropriate groups.
- Bill
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 6, 2010 11:12 AM
snapshots.png (25.7 KB)
Hi Bill,
Attached please find a Microsoft png file that contains two images: a snapshot of the instance and a snapshot of the security group 'webtest' associated with the instance.
I am getting desperate and I really appreciate your help!
Thanks,
Vincent
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 6, 2010 11:27 AM
Vincent,
Sorry you're having trouble. What little I am able to glean off your screenshot, tells me that your instance was launched with the 'webtest' group. So all permissions specified in this group should be valid. I see that you are allowing all tcp traffic on all ports to 0.0.0.0/0 (while this is very dangerous -- which means that hackers will have free access to your server -- and you should really rethink this -- it does mean the amazon level firewall is set up).
So if I am not able to connect to your webserver on port 80 or 8080, I can only conclude that the server is NOT running on these ports (or, else a firewall on your server) is prevent ingress traffic. Can you verify this?
I realize that you're desperate but this trial-and-twenty-questions style is the only method I can use to help..
- Bill
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 6, 2010 8:16 PM
Hi Bill,
I remotely connected to my instance just now and verified that http://localhost still works.
So you are saying a firewall on the instance may be preventing ingress traffic? I thought the firewall that I created security group for is the only firewall on the instance, and the permission rules that I created for port 80 grant access for port 80. Is there another firewall running on the instance? How can I tell?
I am using a windows 2008 basic server instance and I noticed that someone else reported the same issue accessing his instance. Is this a general issue?
Thanks,
Vincent
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 7, 2010 1:25 AM
Hi biwood64
The Security Group is a Firewall that AWS provides by default. However, it does not run within the instance. It is completely independent of your instance so if you are running an Operating System that has its' own Firewall, then you will also need to configure that accordingly.
Changes you make to the Security Groups won't impact the configuration of any internal instance Firewall.
So, if you are running Windows Server 2008, you should check the configuration of its' Firewall to confirm it is configured to allow traffic on the ports you require (port 80).
The following document might also be of interest: http://awsmedia.s3.amazonaws.com/pdf/AWS_Security_Whitepaper.pdf
Re: Can't connect to the web server on an EC2 instance
Posted on: Jul 7, 2010 3:19 PM
I configured the Windows 2008 server firewall to allow HTTP port 80 inbound access. Now I am able to access the web server on the instance. Thanks!
Re: Can't connect to the web server on an EC2 instance
Posted on: Apr 21, 2017 9:17 AM
I am new to aws and have very little networking knowledge.
I have set up an EC2 instance and installed sucessfully
  • MongoDB
  • my nodejs app server and
  • my angular web app on the same instance
My EC2 instance id is i-0e7b2a1b0cc94ba02.
I tried to access my web server from a browser using
https://ec2-54-255-239-55.ap-southeast-1.compute.amazonaws.com:3443/
and
ec2-54-255-239-55.ap-southeast-1.compute.amazonaws.com:3443/
but have not been successful so far. The error message :
This site can’t be reached
ec2-54-255-239-55.ap-southeast-1.compute.amazonaws.com refused to connect.
I need help.
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