If you server plan includes 1x IPv6 subnet, you will receive both 1x IPv6 address and IPv6 prefix.

Prefixes in our network are delegated through DHCP.

We will use a Debian 13 fresh install to see how to setup your DHCP client to receive right lease.

First of all, let's check our interface name and we'll see if our server got IPv6 address /128 by typing command ip addr

Here we can see, that our interface name is eth0 and we have both IPv4 and IPv6 addresses. Some DHCP clients will request prefix by default, but we have to make a manual change to our configuration file. In our case it's /etc/dhcpcd.conf

Filename and path depends on your OS and DHCP client, do your own research before configuring anything.

We have to provide our DHCP client with following parameters:

ia_na 1 - we're requiesting an address

ipv6rs - router solicitation

ia_pd 0 - requesting the prefix with index 0 ( our DHCP server will give you the first available one )

After saving the changes, we have to reload this interface via command

ip link set down eth0 && ip link set up eth0

And after that our network is set up. To verify that we actually got a lease we may use journalctl -f to see our prefix details.