It’s Time Again… Manual SSL Renewal with Let’s Encrypt (Netcup DNS TXT Step-by-Step)

Описание: It’s that time again — the SSL certificate expired 😅
In this tutorial I’ll walk you through renewing an SSL certificate manually using Let’s Encrypt (Certbot) with Netcup as your DNS provider (DNS TXT / _acme-challenge validation).

✅ What you’ll learn:

How to check your current certificate details

How to confirm your domain’s name servers (Netcup)

How to renew using Certbot manual DNS challenge

How to verify the TXT record with dig (and avoid failed validation)

Final browser check (incognito to avoid caching)

⚠️ Important tip: DNS propagation takes time. Don’t rush.
Use the dig TXT check more than once — you may still see old values. In my case it took ~20 minutes.

Commands used in this video

Displays certificate details
sudo certbot certificates

Install the tools we need
sudo apt install dnsutils

To check NS
dig NS -domain- +short

Command for renewal of Certificate with cert bot
sudo certbot certonly --manual --preferred-challenges dns \
--cert-name --domain.name--\
d --domain.name- -d "*.--domain.name--"

Command to check if the TXT is added
dig TXT _acme-challenge.--domain.name-- @1.1.1.1 +short

📌 Replace placeholders:

-domain- / -domain.name- with your real domain (example: example.com)

Quick checklist

Run Certbot renewal command

Copy TXT value

Add it in Netcup DNS (_acme-challenge)

Save changes + wait

Verify with dig until correct value appears

Press Enter to finish validation

Verify in browser (incognito mode)

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