I am trying to install [`LetsEncrypt`](https://letsencrypt.org/) on my server (which I have root SSH access to), for `staging.dnslaude.com` - which is a publicly accessible domain, pointing to `213.212.81.89`.

The server is running `ubuntu 16.04`, and an `nginx` web-server. Below is the `nginx` config:

```
server {
  listen 80;
  server_name staging.dnslaude.com;

  root /path/to/webroot;

  location ^~ /.well-known/acme-challenge/ {
    try_files $uri $uri/ =404;
  }
  rewrite ^(.*) https://$host$1 permanent;
}

server {
  listen 443;
  ssl on;
  ssl_certificate /path/to/self/signed/certificate.crt;
  ssl_certificate_key /path/to/key.key;

  server_name staging.dnslaude.com;

  root /path/to/webroot;

  # ....

  location ^~ /.well-known/acme-challenge/ {
    try_files $uri $uri/ =404;
  }
}

```

You can see that the `nginx` config *appears* to work, as I have manually placed a file in the `acme-challenge` folder [here](http://staging.dnslaude.com/.well-known/acme-challenge/test).

However, when I run the command:

```
letsencrypt certonly --webroot -w /path/to/webroot -d staging.dnslaude.com

```

It returns the following error:

> 
> Failed authorization procedure. staging.dnslaude.com (http-01):
>  urn:acme:error:connection :: The server could not connect to the
>  client to verify the domain :: Could not connect to
>  staging.dnslaude.com
> 
> 
> IMPORTANT NOTES:
>  - The following errors were reported by the server:
> 
> 
> Domain: staging.dnslaude.com Type: connection Detail: Could
>  not connect to staging.dnslaude.com
> 
> 
> To fix these errors, please make sure that your domain name was  
> 
>  entered correctly and the DNS A record(s) for that domain  
> 
>  contain(s) the right IP address. Additionally, please check that  
> 
>  your computer has a publicly routable IP address and that no  
> 
>  firewalls are preventing the server from communicating with the  
> 
>  client. If you're using the webroot plugin, you should also verify  
> 
>  that you are serving files from the webroot path you provided.
> 
> 
> 

I followed the basic setup guide outlined [here](https://certbot.eff.org/#ubuntuxenial-nginx), and have tried all sorts of configuration variations, such as those suggested [here](https://github.com/letsencrypt/acme-spec/issues/221). However, I cannot get past the above error - and cannot see anything in a log file to indicate the cause.

Any suggestions?