Port reservation does Docker hold a different ip address?

Running Docker 4.31 on windows 11
Does anyone knows if Docker holds a different IP address and bridges the public IP to the PC?
My DNS server works fine, yet I can’t get port 443 open.
Some people suggested that there might be an issue witn Docker and DNS conflict.
My DNS is managed by DuckDNS and it looks all good.

any thoughts or suggestions?

That’s Docker Desktop version, not Docker (Docker CE)

What does the DNS server has to do with the port number? What do you want to access and where?

Docker Desktop is a virtual machine with a GUI so it will have its private IP but nothing that would be seen as source IP when a container communicates with an external service on a remote machine.

Here is an overview of What Docker Desktop is

I am trying to run nextcloud
I need port 443 open and it keeps showing as closed
So someone suggested to check that the DNS is pointed correctly and it looks like it is

And how do you run the nextcloud container? Did you forwarded the port correctly? Did you check container logs? What exactly do you get when trying to access it from browser? If it is a white page that probably means the port works, otherwise the browser gives you an error message.

When you share commands or configs about how you ran the container, follow this guide to format your post: How to format your forum posts

The error I am getting
The domain is not reachable on Port 443 from within this container. Have you opened port 443/tcp in your router/firewall? If yes is the problem most likely that the router or firewall forbids local access to your domain. You can work around that by setting up a local DNS-server.

Nextcloud AIO v8.3.0

Container log:
2024-06-06 13:49:53 
2024-06-06 13:49:53 If your server has port 80 and 8443 open and you point a domain to your server, you can get a valid certificate automatically by opening the Nextcloud AIO Interface via:
2024-06-06 13:49:53 https://your-domain-that-points-to-this-server.tld:8443
2024-06-07 00:00:24 Deleted Images:
2024-06-07 00:00:24 untagged: nextcloud/aio-watchtower@sha256:1a6a02a45df6ef8c9b429ea799cb31ebb8de49df46e86023915b106c1b0fb870
2024-06-07 00:00:24 deleted: sha256:abac49a3795c12aab5e75e545d2e90159defabd4c27e0facccbadb2b9c3c949e
2024-06-07 00:00:24 deleted: sha256:4803ee07a247d8a378e3ffb6957d06934bf14aa619cd9fa0f1a39611616476f5
2024-06-07 00:00:24 deleted: sha256:bbce9818f196af5fbb10ca6a0f9903894e3c249acee5a25d9c0095bf9bf2823b
2024-06-07 00:00:24 deleted: sha256:fb9655f83b491c4b283019a56f0c8bfa7313212956f0b432129212a7bac85a45
2024-06-07 00:00:24 untagged: nextcloud/aio-domaincheck@sha256:987946a9aed14fe927b50090e099edc87c72d26e87802eed5d365301e82a3db1
2024-06-07 00:00:24 deleted: sha256:f6412b375048ab1a753e49978707c5a6eb9b0d392118d04a69fff9890315caf4
2024-06-07 00:00:24 deleted: sha256:c008593043b0f334c0147dc494225bf9ef506a470961fda6489e611e11e6b521
2024-06-07 00:00:24 deleted: sha256:9e04a867b4486a3b03333872dbfb89d592b1f9ab575b8e3eb14b2d1e52d6d291
2024-06-07 00:00:24 deleted: sha256:53858128cbdf0acd7b05c556f4f29c864672cf4729b1bace464060687880d4b6
2024-06-07 00:00:24 
2024-06-07 00:00:24 Total reclaimed space: 27.3MB
2024-06-07 15:56:05 Initial startup of Nextcloud All-in-One complete!
2024-06-07 15:56:05 You should be able to open the Nextcloud AIO Interface now on port 8080 of this server!
2024-06-07 15:56:05 E.g. https://internal.ip.of.this.server:8080
2024-06-07 15:56:05 ⚠️ Important: do always use an ip-address if you access this port and not a domain as HSTS might block access to it later!
2024-06-07 15:56:05 
2024-06-07 15:56:05 If your server has port 80 and 8443 open and you point a domain to your server, you can get a valid certificate automatically by opening the Nextcloud AIO Interface via:
2024-06-07 15:56:05 https://your-domain-that-points-to-this-server.tld:8443
2024-06-07 15:58:46 Deleting duplicate sessions

Please, read my previous post again and try to answer all questions so I can understand your issue better. I also had to make the logs a code block The formatting guide I linked applies to the logs as well. Thank you.

Sorry let me try again. Though I am still confused as to what is required from me re formatting. So please forgive me.

And how do you run the nextcloud container? The container is run on a windows 11 PC with Docker

Did you forwarded the port correctly? I use Google WIFI router. The PC is a static IP and the port 443 is forwarding per the app TCP and UDP.

Did you check container logs? I did and posted the logs in previous reply

What exactly do you get when trying to access it from browser? I posted the error message I am getting in the previous reply. Also I ran port different online checkers, all tell me that port 443 is closed.

If it is a white page that probably means the port works, otherwise the browser gives you an error message. - No white page.

I hope I responded in the correct manner. If not please be patient with me and I will imptove. :slight_smile:

Have you read the guide I linked? Since I already fixed the formatting, you don’t have to do anything with your previous post, just when you share new commands, logs, anything with special characters. Details in the linked guide.

If someone tells you that, would you be able to reproduce the container? I referred to the following in my previous posts:

Sorry if I wasn’t clear. So please, share the commands you used to run the container or if you have a compose yaml file which describes the parameters of the container, share that too unless it is a project that you are not allowed to share. In that case, create another example which gives you the same error and share that.

I mean’t from the host to the container. If you just run a container that has its own private IP and you have to forward a host port into the container. If you share the commands and compose file that shows whether you forwarded i correctly or not.

So that was from the browser. Thank you, it was not 100% clear to me as it looked like an error message given by an application, possibly by Nextcloud itself. That means you could access the container perfectly, but it tries to access something but can’t.

Thank you so much.

  1. I did read but still confused
  2. Re And how do you run the nextcloud container? - It automatically runs in Docker. I can stop and restart it by clicking on the Stop/Play Icon. I am not savvy enough to do much beyond this. I do not use any commands and I did not configure anything on my own.
  3. I mean’t from the host to the container. If you just run a container that has its own private IP and you have to forward a host port into the container. If you share the commands and compose file that shows whether you forwarded i correctly or not. - I Don’t know how to do this. Maybe that is what I am missing???
  4. I do not know how to access the container. I only know that I can open Docker Dsahboard and see if the container is Green or Grey. I can start and stop the service by clicking the Play / Stop Icon.
    Currently there are 3 containers and 2 are running (green)

nextcloud-aio-mastercontainer - running (green)

nextcloud-aio-watchtower - Shows Exited (Grey)

nextcloud-aio-domaincheck - Running (green)

I hope that helps