pfSense

RADVD runs when it shouldn't. I have a test system without a WAN interface and IPv6 via SLAAC. RADVD starts and if kill restarts after an interval.

(This bug tracker is too sensitive to typos)
RADVD runs when it shouldn't. I have a 2.3-Release test system without a WAN interface and LAN IPv6 via SLAAC. RADVD starts and if killed restarts after an interval.

2.3-RELEASE (amd64)
built on Mon Apr 11 18:10:34 CDT 2016
FreeBSD 10.3-RELEASE

Do you mean something other than this:
ServicesDHCPv6 Server & RA
The DHCPv6 Server can only be enabled on interfaces configured with a static IPv6 address. This system has none.

where you have a single interface assigned, it didn't unset the dhcpdv6/RA config there for the LAN. That was fixed in a different ticket. You can manually edit that out of your config.

I looked a bit harder at this because my last results were confusing. With no WAN interface and LAN via SLAAC the system emits one RA at boot time and then stops radvd -- at least radvd isn't running when I look on the pfSense box.

# based on Router Advertisement from fe80::fef5:28ff:fed3:5f7a
# received by interface eth0
#

interface eth0
{
        AdvSendAdvert on;
        # Note: {Min,Max}RtrAdvInterval cannot be obtained with radvdump
        AdvManagedFlag on;
        AdvOtherConfigFlag on;
        AdvDefaultLifetime 0;
        AdvLinkMTU 1500;
        AdvIntervalOpt on;

        prefix fdc9:3259:7abf::/64
        {
                AdvValidLifetime 7200;
                AdvPreferredLifetime 1800;
        }; # End of prefix definition

        route fdc9:3259:7abf::/48
        {
                AdvRouteLifetime 7200;
        }; # End of route definition

        RDNSS fdc9:3259:7abf::1
        {
                AdvRDNSSLifetime 1800;
        }; # End of RDNSS definition

        DNSSL lan
        {
                AdvDNSSLLifetime 1200;
        }; # End of DNSSL definition

}; # End of interface definition

"You can manually edit that out of your config."
I'm having trouble finding that ticket. Is it something other than setting ramode to disabled?

just cut out all of <dhcpdv6> through </dhcpdv6> or yeah ramode to disabled.