Nextcloud on IPv6 only

[F_Wechsel]

Hi, I installed Nextcloud via Turnkey LXC Container on my Proxmox VE Webserver. The Server is fully online, but I have no more IPv4 addresses available, for exclusive Nextcloud Installations.
So I installed NExtcloud over IPv6 only. So far so good and Nextcloud is working, I can upload FIles and it seems full functional. Unfortunately the backend seems to have zero internet connection.
I do not see any apps in the appstore, can not connect to the update server and get the “no internet connection error” in the maintenance settings of Nextcloud.
Any clou how to solve this? Installing it with an IpV4 everything in the backend works fine.
As DNS Provider I use cloudflare and have only a proxied AAAA Record for the Domain Name, even SSL works out of the box.
Is there a way to get this to work without a IpV6 at all?
Help would be nice…

[wwe]

I’m not familiar with LXC but it sounds similar to IPv6 only, can't connect to itself - please review your container config and verify it has valid outbound IPv6 connection (public IP, routes, firewall etc.)

I found additional steps might be required to enable IPv6 in Proxmox and LXC

• No IPV6 for LXC container | Proxmox Support Forum
• IPv6 without NAT inside LXC container - LXC - Linux Containers Forum

to verify IPv6 works inside of the container run curl -v --ipv6 https://apps.nextcloud.com which should produce similar output

*   Trying [2a01:4f9:6a:1de8::2]:443...
* Connected to apps.nextcloud.com (2a01:4f9:6a:1de8::2) port 443 (#0)
* ALPN: offers h2,http/1.1
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
*  CAfile: /etc/ssl/certs/ca-certificates.crt
...

[F_Wechsel]

Thanks for your reply! I am one step further. After adding the free and public NAT64 Cloudflare Server to the Container DNS settings helped and got me one step further. I guess the NAT64 server translates IPv6 to IPv4 addresses and brings internet connection back to nextcloud.

I got rid of the “no internet connection” error in nextcloud settings.
I am able to update Nextclpoud via Interface now, which is fine.
Apps are alos loading in the appstore…

BUT trying to download an app gives me a new error now:

ConnectException
cURL error 7: Failed to connect to github.com port 443 after 0 ms: Couldn't connect to server (see https://curl.haxx.se/libcurl/c/libcurl-errors.html) for https://github.com/nextcloud-releases/whiteboard/releases/download/v1.0.1/whiteboard-v1.0.1.tar.gz
could not enable apps

Unfortunately I can not use your curl command. The TurnkeyNextcloud answer is:

~# curl -v --ipv6
curl: no URL specified!
curl: try 'curl --help' or 'curl --manual' for more information

[wwe]

@F_Wechsel

~# curl -v --ipv6
curl: no URL specified!

it must be >>> curl -v --ipv6 https://apps.nextcloud.com <<< or for the other case curl -v --ipv6 https://github.com/nextcloud-releases/whiteboard but it seems there is no IPv6 connection available for Github

 resolve-dnsname github.com

Name                                           Type   TTL   Section    IPAddress
----                                           ----   ---   -------    ---------
github.com                                     A      38    Answer     140.82.121.4

looks you need IPv4 or you must download the apps manually Manual install of a nextcloud app - ꧁ⅴØɨᖙƙr4ʄߙ꧂

[F_Wechsel]

I found a solution.

I added a second Linux Bridge with rerouting IPv4 to IPv6.
All services are online now and nextcloud is working like it is installed with an IPv4 address. Thanks to cloudflares proxied IPv6 I also get IPv4 for my Nextcloud instance from cloudflare, so should be now reachable also from IPv4 only networks.

auto vmbr192
iface vmbr192 inet static
       address 192.168.0.1/24
       bridge-ports none
       bridge-stp off
       bridge-fd 0

       post-up   echo 1 > /proc/sys/net/ipv4/ip_forward
       post-up   iptables -t nat -A POSTROUTING -s '192.168.0.1/24' -o vmbr0 -j MASQUERADE
       post-down iptables -t nat -D POSTROUTING -s '192.168.0.1/24' -o vmbr0 -j MASQUERADE
       post-up   iptables -t raw -I PREROUTING -i fwbr+ -j CT --zone 1
       post-down iptables -t raw -D PREROUTING -i fwbr+ -j CT --zone 1