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

No radvd or dhcp configuration. NetworkManager supports static configuration.

SLAAC without DNS configuration

/etc/radvd.conf:

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

DNS queries typically use IPv4. NetworkManager supports this configuration and it also works when device is ignored by NetworkManager.

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. NetworkManager currently supports RDNSS but not DNSSL. NetworkManager has problems with RDNSS but they have to be solved on IETF level.

SLAAC with DHCPv6 Information Request

/etc/radvd.conf:

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

/etc/dhcp/dhcpd6.conf:

subnet6 2001:db8:1:2::/64 {
    option dhcp6.name-servers 2001:db8:1:2::ab;
    option dhcp6.domain-search "example.net";
}

This is often used to supply DNS information to hosts that don't support RDNSS/DNSSL in Router Advertisements. NetworkManager fully supports this configuration.

DHCPv6 address and DNS configuration

/etc/radvd.conf:

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

/etc/dhcp/dhcpd6.conf:

subnet6 2001:db8:1:2::/64 {
    option dhcp6.name-servers 2001:db8:1:2::ab;
    option dhcp6.domain-search "example.net";
    range6 2001:db8:1:2::1:0000 2001:db8:1:2::1:ffff
}

This is a typical DHCPv6 configuration. Note that routing information are stil delivered through Router Advertisements. NetworkManager fails in this scenario.