Run Yunohost with IPv6 only

[Klut]

What type of hardware are you using: Virtual machine
What YunoHost version are you running: 12.1.36
How are you able to access your server: SSH
Direct access via physical keyboard/screen
Are you in a special context or did you perform specific tweaking on your YunoHost instance ?: removed IPv4 address vom network card and added “nameserver ::1” in resolv.conf

Describe your issue

Apart from the loopback, there is only one network card in the server. I removed the IPv4 address from the network card to force Yunohost to use IPv6. This is because IPv4 is already in use for the productive Yunohost environment. I wanted to use only IPv6 for the test environment, as I have a dual-stack connection and am therefore assigned a real public IPv6 address by my ISP.

Share relevant logs or error messages

args:
domain: maindomain.tld
dry_run: false
force: true
ended_at: 2025-12-04 09:55:15.166887
error: “Konnte die IP-Adresse f\xFCr DynDNS nicht aktualisieren”
interface: cli
operation: dyndns_update
parent: null
related_to:

• • domain
  • maindomain.tld
• • domain
  • maindomain.tld
    started_at: 2025-12-04 09:55:13.703269
    started_by: ******
    success: false
    yunohost_version: 12.1.36

============

2025-12-04 10:55:14,738: INFO - Update needed, going on…
2025-12-04 10:55:14,836: DEBUG - Reusing IPv4 from cache: None
2025-12-04 10:55:14,836: DEBUG - Reusing IPv6 from cache: xx:xx:xx:xx:xx:xx
2025-12-04 10:55:15,161: DEBUG - Formating result in ‘export’ mode
2025-12-04 10:55:15,165: DEBUG - Now pushing new conf to DynDNS host…
2025-12-04 10:55:15,165: DEBUG - id 48878
opcode UPDATE
rcode NOERROR
flags
;ZONE
ynh.fr. IN SOA
;PREREQ
;UPDATE
maindomain.tld. ANY ANY
maindomain.tld. ANY ANY
maindomain.tld. ANY ANY
mail._domainkey.maindomain.tld. ANY ANY
_dmarc.maindomain.tld. ANY ANY
*.maindomain.tld. ANY ANY
maindomain.tld. ANY ANY
maindomain.tld. 3600 IN AAAA xx:xx:xx:xx:xx:xx
maindomain.tld. 3600 IN MX 10 diem25
maindomain.tld. 3600 IN TXT “v=spf1 a mx -all”
mail._domainkey.maindomain.tld. 3600 IN TXT “v=DKIM1; h=sha256; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC0Tx+xP691hzS0+iX4LNxLvYUKcfdJGPsxXGVhtTE+Ouv6xX837kNyvW/D3zcrflZHmfamTGSn1nU+NUvUMPAK9NeZsv4KjybWqCOmhL5rh/QBU5XA0V5ZpgeWdAi89Xar3WZ2S+UPtz+CBeM1RZaY0NQ4vDzpe9aVmzHJrPnnUQIDAQAB”
_dmarc.maindomain.tld. 3600 IN TXT “v=DMARC1; p=none”
*.maindomain.tld. 3600 IN AAAA xx:xx:xx:xx:xx:xx
maindomain.tld. 3600 IN CAA 0 issue “letsencrypt.org”
;ADDITIONAL
2025-12-04 10:55:15,166: ERROR - [Errno 101] Network is unreachable

[rungeard]

IPv6-only support

[otm33]

Have you checked the routes?

[TabTwo]

how did you manage to install yunohost?

I got some errors during postinstall

[Klut]

The post-installation process is the final part of deploying a YunoHost instance. I have successfully completed this several times. It is important that you have enough disk space and RAM available on your server hardware. This also applies to VMs.

Do not make any changes in the operating system during the setup! This also applies to the final step of the post-installation. Follow the installation steps in sequence up to and including the post-installation. Then there should be no problems.

If you want to make changes directly to the operating system settings, do so only after the post-installation has been successfully completed.

[Klut]

All routes in the routing tables of both YunoHost instances are automatically generated dynamic routes of the respective operating system.

Both YunoHost instances are operated on an end customer VDSL connection with full dual stack. Port forwarding for IPv4 is set up so that the public IPv4 address from my ISP is forwarded to the productive YunoHost instance (per port or port range). The productive YunoHost instance also has its own public IPv6 address, which is also forwarded to this server.

However, in order to be able to run a YunoHost test instance with its own DNS name space in parallel, it should only have host AAAA entries so that the two YunoHost instances do not interfere with each other.

In the Advanced menu under YunoHost settings, you can configure the diagnostics to skip IPv4 checks. It would be nice if there were a switch that could completely disable IPv4 on the network interface used. But as long as you could only set the AAAA entries in the DNS, that would already be a suitable solution.