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The standard ACL functionality in IPv6 is similar to standard ACLs in IPv4. Access lists determine what traffic is blocked and what traffic is forwarded at device interfaces and allow filtering based on source and destination addresses, inbound and outbound to a specific interface. Each access list has an implicit deny statement at the end. IPv6 ACLs are defined and their deny and permit conditions are set using the ipv6 access-listcommand with the deny and permit keywords in global configuration mode.

IPv6 extended ACLs augments standard IPv6 ACL functionality to support traffic filtering based on IPv6 option headers and optional, upper-layer protocol type information for finer granularity of control (functionality similar to extended ACLs in IPv4).

The following header fields are used for IPv6 inspection: traffic class, flow label, payload length, next header, hop limit, and source or destination IP address. For further information on and descriptions of the IPv6 header fields, see RFC 2474.

Filtering incoming and outgoing connections to and from the device based on an IPv6 ACL is performed using the ipv6 access-class command in line configuration mode. The ipv6 access-class command is similar to the access-class command, except the IPv6 ACLs are defined by a name. If the IPv6 ACL is applied to inbound traffic, the source address in the ACL is matched against the incoming connection source address and the destination address in the ACL is matched against the local device address on the interface. If the IPv6 ACL is applied to outbound traffic, the source address in the ACL is matched against the local device address on the interface and the destination address in the ACL is matched against the outgoing connection source address. We recommend that identical restrictions are set on all the virtual terminal lines because a user can attempt to connect to any of them.

1.    enable


2.    configure terminal


3.    ipv6 access-list access-list-name


4.    permit source-ipv6-prefix/prefix-length host


5.    deny protocol source-ipv6-prefix/prefix-length eq telnet any


6.    exit


7.    interface type number


8.    ipv6 traffic-filter access-list-name {in | out}


9.    end


10.    show ipv6 access-list [access-list-name]

Device> enable 

Device# configure terminal 

Device(config)# ipv6 access-list ipv6acl 

Device(config-ipv6-acl)# permit 2001:DB8:1::1/32 any

Device(config-ipv6-acl)# deny tcp 2001:DB8:0300:0201::/32 eq telnet any 

Device(config-ipv6-acl)# exit 

Device(config)# interface Gigabitethernet 1/0/2 

Device(config-if)# ipv6 traffic-filter ipv6acl out 

Device(config-if)# end 

Device# show ipv6 access-list 

Device# show ipv6 access-list

IPv6 access list ipv6acl
    permit tcp any any eq bgp reflect tcptraffic (8 matches) sequence 10
    permit tcp any any eq telnet reflect tcptraffic (15 matches) sequence 20
    permit udp any any reflect udptraffic sequence 30

IPv6 access list tcptraffic (reflexive) (per-user)
    permit tcp host 2001:DB8:1::32 eq bgp host 2001:DB8:2::32 eq 11000 timeout 300 (time left 243) sequence 1
    permit tcp host 2001:DB8:1::32 eq telnet host 2001:DB8:2::32 eq 11001 timeout 300 (time left 296) sequence 2

IPv6 access list outbound
    evaluate udptraffic
    evaluate tcptraffic