Listen on a different ip

When using Hetzner servers each server gets assigned to a ipv6 address space like 1234:5678:90ab:cdef::/64. The 64 means that the first 64 bits are part of the network prefix and the rest are the host addresses (which can be assigned).

When a server should listen on more than one of these addresses it can be configured in netplan by adding a new entry to /etc/netplan/<name-of-the-file> in network.ethernets.eth0.addresses.

To apply this setting temporary: sudo netplan try -timeout 180 where 180 are the seconds until reset.

To apply permanently: sudo netplan apply

Specifying the listen IP in Apache

Edit /etc/apache2/ports.conf Instead of Listen 80type `Liste [1234:5678:90ab:cdef::9]:80 as described here

After that the new IP address needs to be configured in the /etc/apache2/sites-available/<name-of-vhost>.conf file like: <VirtualHost [1234:5678:90ab:cdef::9]:80>

See also

host-a-website-on-a-different-port