From Fedora Project Wiki

NetworkManager supports the IPv6 protocol. IPv6 is typically used in one of the following configurations. Network setup is typically done by the local router and, if necessary, DHCP server.

In the following examples, we assume that radvd resides on the router and DHCP is on the local network (possibly also on the router).

== Static configuration

== SLAAC without DNS configuration

/etc/radvd.conf:

interface eth0 {
    AdvSendAdvert on;
    prefix 2001:db8:1:2::/64 {};
};

DNS queries typically use IPv4.

SLAAC with RDNSS and DNSSL

/etc/radvd.conf:

interface eth0 {
    AdvSendAdvert on;
    prefix 2001:db8:1:2::/64 {};
    RDNSS 2001:db8:1:2::ab {};
    DNSSL example.net {};
};

The contents of host's /etc/resolv.conf is filled in by NetworkManager.

== SLAAC with DHCPv6 Information Request

/etc/radvd.conf:

interface eth0 {
    AdvSendAdvert on;
    AdvOtherConfigFlag on;
    prefix 2001:db8:1:2::/64 {};
};

This is often used to supply DNS information to hosts that don't support RDNSS/DNSSL in Router Advertisements. NetworkManager currently supports RDNSS but not DNSSL.