I would like to get a letsencrypt.org SSL certificate for a service which runs on a non-default root-reserved port, i.e. port other than 443 and < 1024, e.g. 446. I'm uncertain whether letsencrypt.org supports this setup because I only found a feature request and a github.com issue which run into a discussion loop and are closed for no apparent reason. Maybe someone knows the answer right-away or cares to extract a clear statement which is hard to do for me because there're tons of references and developers and non-developers are talking confused.

I tried to specify domain:port as domain to letsencrypt console client which fails because it's not FQDN (sudo letsencrypt certonly -a manual -d [domain]:446--test-cert fails due to Requested domain [domain]:446 is not a FQDN) and adding --http-01-port 446 doesn't help.


1 Answer 1


Yes you can use non-default ports and it's recommended for compability with browsers and firewalls to use port above 1024 like 8443. You do not need to specify port when obtaining certificate. You just do it as usual and then you can experiment with changing ports.

Some configurations and software may refuse to pass HTTPS traffic to ports below 1024 other than default 443. For example, some corporate firewalls.

  • That works. I was suffering for an errornous web server configuration. Aug 7, 2016 at 13:39

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