Update DHCPv6 server requirement (#3541)

Co-authored-by: Maximilian Kolb <[email protected]>
Co-authored-by: Ewoud Kohl van Wijngaarden <[email protected]>

guides/common/modules/con_requirements-for-installation-in-an-ipv6-network.adoc

@@ -3,9 +3,8 @@
 
 Before installing {Project} in an IPv6 network, ensure that you meet the following requirements:
 
-* You must deploy an external DHCP IPv6 server as a separate, unmanaged service to bootstrap clients into GRUB2.
-GRUB2 configures IPv6 networking by using DHCPv6 or by assigning a static IPv6 address.
-This is required because the DHCP server in {RHEL} (ISC DHCP) does not provide an integration API for managing IPv6 records, therefore the {SmartProxy} DHCP plugin that provides DHCP management is limited to IPv4 subnets.
+* You must deploy an external DHCPv6 server and cofigure it manually to communicate with the network boot process and to manage IP address assignment because {Project} cannot integrate with a DHCPv6 server and manage its configuration.
+For more information about DHCPv6 server configuration, see {ProvisioningDocURL}options-in-unmanaged-dhcpv6[Options in unmanaged DHCPv6] in _{ProvisioningDocTitle}_.
 
 ifdef::satellite[]
 * You must deploy an external HTTP proxy server that supports both IPv4 and IPv6.