Problem Accessing Ports 443 and 80 on an Ubuntu VM

Question

Problem Accessing Ports 443 and 80 on an Ubuntu VM

Connor Wynne 1

Ports 80 and 443 can not be accessed in the VM. NSG is set to allow traffic inbound on both and the ufw is disabled. Network outside of the VM is allowing traffic on both 80 and 443.

vipullag-MSFT 26,492 Reputation points Moderator

2021-11-16T04:47:59.08+00:00

@Connor Wynne

Based on your ask, looks like you are able to access the VM Public IP on ports 80 and 443 from outside successfully as you mentioned the traffic is allowed on NSG's correctly.
(So accessing the VM Public IP via this link on the ports 80 and 443 shows as open).
If this is the case then the NSG's impacting the Subnet of the VM and the internal firewall are all good as expected.

Now, if your issue is that these ports are not accessible within the VM, then it depends on the services that are running on these ports.
Please check the status of the services that are configured on these ports.
Can you share more details of the issue like what are the services/apps that are using/running these ports. What web application is deployed and How is application configured to use these ports.

If possible share the architecture diagram of your application, to understand and assist you better.
Connor Wynne 1 Reputation point

2021-11-16T12:16:20.84+00:00

No I can not access them from the outside. That's my problem basically. I've configured the NSG correctly but can not access the ports from the outside. When I ping them from that website it says they're closed. I've disabled APACHE2 which was running on port 80, as far as I know, nothing should be running on port 443.
Connor Wynne 1 Reputation point

2021-11-16T12:19:07.007+00:00

My apologies, I didn't word the question correctly. I'm trying to access my VM from a domain that I'm pointing to my VM public IP, but am unable to do so because port 80 and 443 remain closed to the outside even though I've configured them to allow traffic in the NSG.

2 answers

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vipullag-MSFT 26,492 Reputation points Moderator

2021-11-16T04:47:59.08+00:00

@Connor Wynne

Based on your ask, looks like you are able to access the VM Public IP on ports 80 and 443 from outside successfully as you mentioned the traffic is allowed on NSG's correctly.
(So accessing the VM Public IP via this link on the ports 80 and 443 shows as open).
If this is the case then the NSG's impacting the Subnet of the VM and the internal firewall are all good as expected.

Now, if your issue is that these ports are not accessible within the VM, then it depends on the services that are running on these ports.
Please check the status of the services that are configured on these ports.
Can you share more details of the issue like what are the services/apps that are using/running these ports. What web application is deployed and How is application configured to use these ports.

If possible share the architecture diagram of your application, to understand and assist you better.
Connor Wynne 1 Reputation point

2021-11-16T12:16:20.84+00:00

No I can not access them from the outside. That's my problem basically. I've configured the NSG correctly but can not access the ports from the outside. When I ping them from that website it says they're closed. I've disabled APACHE2 which was running on port 80, as far as I know, nothing should be running on port 443.
Connor Wynne 1 Reputation point

2021-11-16T12:19:07.007+00:00

My apologies, I didn't word the question correctly. I'm trying to access my VM from a domain that I'm pointing to my VM public IP, but am unable to do so because port 80 and 443 remain closed to the outside even though I've configured them to allow traffic in the NSG.

Answer 1

@Connor Wynne

Thanks for clarifying the issue and sharing the details.

Here are few suggestions to try and see if that helps fixing your issue.

Run any of the below commands and check if the ports are listening or not:

sudo lsof -i -P -n | grep LISTEN  
sudo netstat -tulpn | grep LISTEN  
sudo ss -tulpn | grep LISTEN  
sudo lsof -i:80## see a specific port such as 80##

Incase the ports 80 and 443 are not listening, the reason might be there is no program listening on port 80 so it's closed and you can't connect to it (as you have stopped the Apache).
Re-enable the services on the ports and check if the ports are listening or not.

If the ports are not listening, then you can try adding them to internal firewall and ensure to save the firewall changes. Use below commands:

sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT  
sudo iptables -A INPUT -p tcp --dport 443 -j ACCEPT  
sudo service iptables save

Ensure the apache configuration has correct port binding (Listen 80) in the below file.

sudo vi /etc/apache2/ports.conf

Once this is done, you have added the ports to internal firewall and the services are up and running on the required ports. Please try and see the ports are open or not using this link.

If the ports are still showing as closed, then it could be issue with the NSG.

As you mentioned that the ports are allowed on the NSG attached to the VM, there might be other NSG's impacting the subnet in which the VM is deployed.
On the Azure Portal check if the Network interface of the VM has only the NSG that you have created associated with it.

Hope that helps.
Please 'Accept as answer' if the provided information is helpful, so that it can help others in the community looking for help on similar topics.

Answer 2

Gene Gleyzer 0

Everything worked, except the last command was:

sudo /sbin/iptables-save

Gene Gleyzer 0 Reputation points

2023-06-27T21:45:31.7933333+00:00

Thanks!!

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Problem Accessing Ports 443 and 80 on an Ubuntu VM

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