On Thu, Feb 19, 2026 at 14:22:26 +0100, Marco Moock wrote:
> On 19.02.2026 13:20 Greg Wooledge wrote:
>
> > I don't think IPv6 works from this host at all. I tried a few other
> > IPv6 addresses, and couldn't ping any of them. If I'm correct then
> > disabling IPv6 in Postfix (which I've already done) seems like the
> > best solution to that.
>
> That is the worst solution.
> Make sure IPv6 works or remove all GUA addresses from your system, so
> no other application will try to use it and fail.
>
> How did you set it up?
I didn't. I have no idea how IPv6 works, or is intended to work.
I've never seen a system where it works.
This is what the hosting provider provided:
# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group
default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: venet0: <BROADCAST,POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue
state UNKNOWN group default
link/void
inet 127.0.0.2/32 scope host venet0
valid_lft forever preferred_lft forever
inet 199.231.184.176/32 brd 199.231.184.176 scope global venet0:0
valid_lft forever preferred_lft forever
# cat /etc/network/interfaces
# This configuration file is auto-generated.
#
# WARNING: Do not edit this file, your changes will be lost.
# Please create/edit /etc/network/interfaces.head and
# /etc/network/interfaces.tail instead, their contents will be
# inserted at the beginning and at the end of this file, respectively.
#
# NOTE: it is NOT guaranteed that the contents of /etc/network/interfaces.tail
# will be at the very end of this file.
#
# Auto generated lo interface
auto lo
iface lo inet loopback
# Auto generated venet0 interface
auto venet0
iface venet0 inet manual
up ifconfig venet0 up
up ifconfig venet0 127.0.0.2
up route add default dev venet0
down route del default dev venet0
down ifconfig venet0 down
iface venet0 inet6 manual
up route -A inet6 add default dev venet0
down route -A inet6 del default dev venet0
auto venet0:0
iface venet0:0 inet static
address 199.231.184.176
netmask 255.255.255.255
