IPv6 problems with Hetzner installation

[Kimmo H]

Installed virtualserver "filter2" to Hetzner via your .iso (now 6.3-5) which has been working ok, now we installed new debian10 mailserver from Hetzner with IPv6 and we start to have these errors to mail.log

May 20
14:52:48 filter2 postfix/smtp[5703]: connect to mail.xxx.fi[2a01:4f9:c011:36ed::1]:25: Network is unreachable
May 20
14:52:58 filter2 postfix/smtp[5703]: connect to mail.xxx.fi[2a01:4f9:c011:36ed::1]:25: Network is unreachable
May 20
14:52:58 filter2 postfix/smtp[5703]: 76B69C083C: to=<
juha.harkonen@xxx.fi
>, relay=none, delay=0.85, delays=0.01/0/0.84/0, dsn=4.4.1, status=deferred (connect to mail.xxx.fi[2a01:4f9:c011:36ed::1]:25: Network is unreachable)

I try to fix it via Hetzner debian IPv6 instructions, no help.
https://docs.hetzner.com/robot/dedicated-server/network/net-config-debian/

We manage to fix it by disabling IPv6
/etc/sysctl.conf
net.ipv6.conf.all.disable_ipv6 = 1
# sysctl -p


But how can we enable IPv6 support ?

 

[Stoiko Ivanov]

Is the question really for Proxmox Mail Gateway - or is it a general Debian Guest running on Proxmox VE?

In any case - Hetzner has to my knowledge a network setup that is a bit peculiar if you're not used to it - it might be best to ask their support in both situations.

Else - I'd check the network config /etc/network/interface - and the actual config:
`ip -6 a`
`ip -6 r`
and try to ping my default-gateway and various hosts on the internet (e.g. google.com, ...) via IPv6 to see where the problem is.

I hope this helps!

 

[Kimmo H]

i installed VM from your proxmox mail gateway .iso file to Hetzner.

 

[steven99]

i installed VM from your proxmox mail gateway .iso file to Hetzner.

It sounds like a network config issue and as @Stoiko Ivanov mentions, it would be best to talk with hetzner support on what IPv6 settings you need to use. It could be the gateway isn't correct, or the prefix (netmask) isn't, or a few other problems that only they would know what the correct info is. For forum users to help further, we'd need details on the config, the settings it should be, etc.