100 Domain limit, including www and aliases

[robking]

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is:
mytravelsite.co.uk

I ran this command:
Issue a Let's Encrypt certificate to 1 parent domain, and 49 domain aliases, including www prefix.

It produced this output:
Maximum of 100 domains in one order.

My web server is (include version):
CentOS Linux 7.9.2009 (Core)

The operating system my web server runs on is (include version):
CentOS Linux 7.9.2009 (Core)

My hosting provider, if applicable, is:
Ionos

I can login to a root shell on my machine (yes or no, or I don't know):
Yes

I'm using a control panel to manage my site (no, or provide the name and version of the control panel):
Plesk Obsidian
Version 18.0.33 Update #1

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot):
If Let's Encrypt version this is 2.12.6-696 installed as an Extension within Plesk

To explain my setup, I have a parent WordPress multisite installation, running on mytravelsite.co.uk, that has approx 120 subsites. Therefore I need to issue a certificate that covers all of these, including the www prefix. The domain aliases are set up to point to the parent domain, as WordPress then handles all traffic to https://domain.alias to the respective subsite within the mytravelsite.co.uk WordPress parent.

So my question is, can the limit be extended to protect all domain aliases and their www equivalents, and, if not, then can multiple certificates be issued at 50 domains a time, so that all are then protected?

Any advice would be appreciated, as Ionos Server help have directed me here as they aren't able to suggest a solution.

Kind regards,
Rob

[orangepizza]

you can use multiple certificates (buy may need different vhost setting)

[JuergenAuer]

Hi @robking

@robking

as Ionos Server help have directed me here as they aren't able to suggest a solution.

I don't see a Letsencrypt problem.

The 100 domain names limit exists. And that limit is ok.

So it's a Wordpress problem how to configure more then 100 subdomains with different certificates.

[schoen]

@robking

So my question is, can the limit be extended to protect all domain aliases and their www equivalents, and, if not, then can multiple certificates be issued at 50 domains a time, so that all are then protected?

The second strategy should work fine (and is widely used by numerous web sites and web hosts), but as @orangepizza points out, it may require more or different configuration on the server to make it understand your intentions.

Modern web servers (since about 2010, give or take a few years) and web browsers (since about 2006, give or take a few years) have supported a technology that lets the browser ask for a specific site when connecting, which allows the server to choose an appropriate certificate (and, optionally, different content) for each connection.

Server Name Indication

This functionality is a built-in part of all modern web servers, but usually does require some kind of configuration that lets the web server know which certificate goes with which site. The way of doing that depends greatly on the hosting environment.

I think Plesk or WordPress support or communities might be able to help you better if you find it hard to configure that on your server—you could tell them "because of Let's Encrypt limits, I need to get several separate certificates for different domain names that are used in my multisite setup on a single server instance, because Let's Encrypt won't give me a single certificate for all of the names" and then ask how Plesk and/or WordPress typically handles that case. I'm pretty sure you won't be the first person to have asked about this!