For the dhcpv6 server to assign the dns, it must be enabled “Advertise DNS” in IPv6 → ND.

In IPv6, the DHCPv6 server can be configured to assign DNS addresses to clients, as well as other network configuration parameters. DHCPv6 functionality is flexible and allows two main modes of operation that affect how DNS can be assigned:

1. DHCPv6 Stateful

In stateful mode, DHCPv6 works similarly to DHCP on IPv4, assigning not only IP addresses (if necessary) but also other network settings, such as DNS. In this mode, the DHCPv6 server handles the entire address and configuration assignment process, including:

• IPv6 addresses
• DNS
• Default Gateway
• Other network options such as NTP servers

2. DHCPv6 Stateless

In stateless mode, DHCPv6 is mainly used to assign “other configuration parameters” that do not include the IPv6 address, which is generated by the SLAAC (Stateless Address AutoConfiguration) mechanism of the device itself. In this context, stateless DHCPv6 is commonly used to allocate:

• DNS
• Information about domain configuration
• Additional routes

In both configurations, the process of specifying DNS servers is handled through the DHCP configuration option called Option 23 (DNS Recursive Name Server) y Option 24 (Domain Search List). These options allow the DHCPv6 server to provide DNS information to clients, which can use it to resolve domain names.

Configuration on the DHCPv6 Server

To configure a DHCPv6 server on a system such as MikroTik RouterOS, Cisco IOS, or similar systems, you typically need:

1. Define the IPv6 address pool.
2. Specify the DNS options that will be delivered to clients.
3. Activate the DHCPv6 server on the corresponding interface.

For example, in MikroTik RouterOS, you can configure DHCPv6 to assign DNS as follows:

/ipv6 dhcp-server
add name=dhcpv6-server interface=ether1 address-pool=ipv6-pool
/ipv6 dhcp-server option
add code=23 name=dns-server value=0x20010db8000000000000000000000535
add code=24 name=dns-search value=0x0377777706676f6f676c6503636f6d00

This example configures DNS options for the DHCPv6 server, telling clients which DNS servers to use and which domains to search for.

In summary, yes, the DHCPv6 server can assign DNS, and its configuration can be adjusted to meet the specific needs of the network, whether in stateful or stateless mode.