You can now get a free SSL certificate for your host name (for example myhome.d-dns.jp) on D-DNS.JP, the free dynamic DNS service. D-DNS.JP issues it from Let’s Encrypt for you and automatically prepares a new certificate before the current one expires.
How to use it
- On My page, choose to issue an SSL certificate for your host.
- It is usually issued within a few minutes.
- Download the certificate (<host name>.fullchain.pem) and the private key (<host name>.privkey.pem) and set them up on your web server.
- To reach it over https:// from outside, open port 443 on your router.
About the certificate
- Issued by Let’s Encrypt and valid for about 90 days.
- D-DNS.JP automatically prepares a new certificate (with a new key) 30 days before expiry. Download it again and reinstall it on your server.
- Each certificate covers that one host name. Wildcard certificates (*.example.d-dns.jp) are not supported.
- The same certificate works whether visitors connect over IPv4 or IPv6.
Limits
- Free of charge (and, as before, up to three hosts for free).
- Up to 5 requests per account per 30 days. New certificates prepared automatically before expiry are not counted.
- When many requests come in at once, Let’s Encrypt’s rate limits can delay issuance by a few days.
- If issuance fails, D-DNS.JP retries automatically (after 5, 10, 20 and 40 minutes, then every 60 minutes).
See the D-DNS.JP guide (SSL certificates, in Japanese) for details.