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,
Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México