Hi @CobbyJ ,
Are you referring to the ipv6 prefixe(s) being advertised by the router advertisement (RA)? If you want to prevent RA to contain prefixes that the other hosts on the subnet might try to autoconfig themselves from, I would suggest using the following command:
Int Gigx/x
ipv6 nd prefix default no-advertise
Regards,
Regards,
Harold Ritter, CCIE #4168 (EI, SP)