How to add a certname's altname?

So I am using the cert for mongodb tls connections. When I connect to it is working fine, however when I try to use the publicIP:27017 I am encountering error: "Hostname/IP does not match certificate's altnames: IP: publicIP is not in the cert's list"

My domain is:

I ran this command:

It produced this output:

My web server is (include version):

The operating system my web server runs on is (include version): Ubuntu 20.04

My hosting provider, if applicable, is:

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

I'm using a control panel to manage my site (no, or provide the name and version of the control panel):

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): 0.40.0

Let’s Encrypt doesn’t support IP address certificates, so you have to use a domain name.


Yes I have a certificate for my domain name. My only problem is that other clients would be connecting to this either via public/private IP

If you need a certificate for an IP address you can manually request an IP certificate from ZeroSSL but I'm not aware of any ACME enabled certificate authorities which currently have live support for IP address certificates.

If Clients will be connecting to your service via an IP address you should ideally tell them to use the proper domain name which is valid for your certificate instead. You can circumvent certificate name validation in clients that you control (e.g. code you write), but in a standard desktop web browser you can't.


To be extra clear: ZeroSSL does NOT support certs for IP addresses using their ACME API, only with their webinterface. And then you're limited to max. 4 free certs I believe.


As @mcpherrinm said about IP Address certificate;
you can read about that here Let’s Encrypt offers Domain Validation (DV) certificates.

That is an old version of Certbot see Certbot 2.4.0 Release

Tell them to stop doing that. :wink:


:rofl: :rofl: :rofl:

Well, my other clients would be application server since my use case for this cert is for mongodb tls/ssl connections. Communicating to it via private IP would be the ideal scenario. Connecting via public IP/DNS would just be for contingency purposes only :sweat_smile:

Are you sure that you need a publicly-trusted certificate in this case? Could you use a private internal CA instead?


You can use a public DNS name that points to a private IP if you use DNS validation as your method of validating the domain in your ACME client. That way you get a DNS name you can administer (so you can repoint it in the future when migrating servers, without changing your app server clients), and you get a publicly trusted cert from Let's Encrypt so you don't have to run your own CA or use a self-signed cert.

If you do opt to use your own internal CA you could use step-ca (smallstep) or others, the general process is to sign a cert using your own "trust anchor" root certificate then distribute the public cert for that as a CA cert file to your clients. So that way only your internal clients trust the certs issued by your internal CA, and you control the private issuance and use of those certs, but they are untrusted outside of clients you control.


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