SFTP External Storage and ipv6

I have trouble to add a SFTP-Server that has only a IPv6 Address to external Storage.
With filezilla I have no problem connecting to this sftp-server.
Is this even possible to add a server without a IPv4 Address or an IPv6 directly as host?
I’m on Nextcloud 15.0.7


That’s bizarre unless of course your instance is not accepting IPv6 traffic (which it should be at default at most providers).

As I Said, filezilla is working fine. Could it be, that if you enter a Domain it will try ip4 and fails but never tries ip6?
But it also fails with the direct ip like: [ipv6]
Is this even known as a vaild input format?

I’d check that the nextcloud instance is setup with ipv6 interface and address


I tested an IPv6 [myipV6] as host input and got this error at the logs:

Cannot connect to [myipV6]:22. Error 99. Cannot assign requested address at /var/www/html/3rdparty/phpseclib/phpseclib/phpseclib/Net/SSH2.php#1122

This address works with filezilla. So IPv6 is not a valid host input, unfortunately…
should I open up a github bug report?

Found the problem. Was running Nextcloud in a docker container without IPv6 support and address. After activating IPv6 for docker: https://docs.docker.com/v17.09/engine/userguide/networking/default_network/ipv6/
This works even with an IPv6 address. This is not a format issue!

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That is what both of said…

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Yeah forgott the that I put the container into its own docker network and checked from the host console.

Ahh I gotcha on how trouble shooting can be confused with nested virtualization like that.