error duplicate listen options for [::]:443 when trying to add a subdomain to my nginx setup

Posted June 8, 2021 51 views
NginxLet's EncryptUbuntu 18.04

I followed this DigitalOcean guide on how to setup Nginxon an Ubuntu 18.04 droplet. I set up my domain’s nameservers to point to Cloudflare’s and then based on what I had read previously my understanding that to add a subdomain ( in this case) I could simply add a file titled ( to the /etc/nginx/sites-available (and symlink that file with /etc/nginx/sites-enabled)
Keep in mind I am using Let’s Encrypt

However when I add that file and then try to enable that site, I get the following when running sudo nginx -t

nginx: [emerg] duplicate listen options for [::]:443 in /etc/nginx/sites-enabled/
nginx: configuration file /etc/nginx/nginx.conf test failed

Now the config was created by copying the config and modifying it slightly. With the blog subdomain not included in sites-enabled nginx produced no errors in the configs.
I have tried the same procedure to create the config for the subdomain twice, no luck. I have shown the below files to a buncha people who then suggested I try a couple different things like removing the default config from sites-enabled, no luck.
So can anyone please help with this issue?
Also before I forget I intend to deploy Ghost on that blog subdomain

My nginx.conf, config, default config, and configs are attached in the pastebin links below.

Nginx.conf config
default config config

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1 answer

Ok so I looked at this guide and found this:

In this new file, we’re going to have to look at the listen directives again. If you left the default_server option enabled in the last file, you’ll have to remove it in this file. Furthermore, you’ll have to get rid of the ipv6only=on option, as it can only be specified once per address/port combination:```
So I removed the line in the config that contained the ``ipv6only=on`` option.

And it works now.

Please leave this up in case anyone else comes across this issue.
by Justin Ellingwood
Nginx is an incredibly powerful web server and reverse proxy. In this guide, we'll discuss how to set up server blocks on Ubuntu 14.04 in order to server multiple domains from a single server.