Subnet-group

Filter incoming messages based on the subnet that the link-address is in.

Example

<subnet-group>
    prefix 2001:db8:dead::/48
    prefix 2001:db8:beef::/48

    <ignore-request/>
</subnet-group>

Section parameters

prefix (required, multiple allowed)

A prefix that the link-address of the relay or server interface can be in.

Example: “2001:db8:1:2::/64”

Possible sub-section types

Filters (multiple allowed)
Configuration sections that specify filters. A filter limits which handlers get applied to which messages. Everything inside a filter gets ignored if the filter condition doesn’t match. That way you can configure the server to only apply certain handlers to certain messages, for example to return different information options to different clients.
Handlers (multiple allowed)

Configuration sections that specify a handler. Handlers process requests, build the response etc. Some of them add information options to the response, others look up the client in a CSV file and assign addresses and prefixes, and others can abort the processing and tell the server not to answer at all.

You can make the server do whatever you want by configuring the appropriate handlers.