Router(config)#ipv6 access-list protect_IPv4_services
Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq tacacs
Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq domain
Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 1698
Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 1701
Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 1967
Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 2427
Router(config-ipv6-acl)#deny udp any 2001:DB8:1:128::/64 eq 5060
!-- Permit/deny all other Layer 3 and Layer 4 traffic in accordance
!-- with existing security policies and configurations
!
!-- Allow all other IPv6 traffic
Router(config-ipv6-acl)#permit ipv6 any 2001:db8:1:128::/64
!
!
Router(config)#interface FastEthernet0/1
Router(config-if)#ipv6 traffic-filter protect_IPv4_services in