Configuring your Cisco Router for IPv6
The configurations supplied on this page are generic: they may not perfectly suit your network or configuration.
Important Note:
Using these configurations is your own responsibility. Assistance from Internode regarding these configurations may be limited.
Not what you're looking for? Try the Cisco 877/877W/887 configuration guide (IPv4) instead.
- Cisco IPv6 ADSL Configuration
- How do I enable IPv6 and Prefix Delegation on my Cisco Router?
- How do I configure an IPv6 firewall on my Cisco router?
- How do I get IPv6 via wireless on a Cisco 877W?
- Why don't my hosts get IPv6 addresses when I bridge my WLAN and LAN interfaces?
- Why does IPv6 traffic stop working after my PPP session reconnects?
- Cisco IPv6 Native Ethernet
Cisco IPv6 ADSL Configuration
How do I enable IPv6 and Prefix Delegation on my Cisco Router?
! Enable IPv6 ipv6 unicast-routing ipv6 cef ! Enable IPv6 and Prefix Delegation on the WAN interface interface Dialer0 ipv6 address NODE-PD ::FF:0:0:0:1/128 ipv6 enable ipv6 dhcp client pd NODE-PD rapid-commit ipv6 route ::/0 Dialer0 ! Enable IPv6 and Prefix Delegation on the LAN interface interface Vlan1 ipv6 address NODE-PD ::1/64 ipv6 enable ipv6 nd other-config-flag ipv6 dhcp server NODE-DHCPV6 ! Enable stateless DHCPv6 for DNS configuration ipv6 dhcp pool NODE-DHCPV6 dns-server 2001:44B8:1::1 dns-server 2001:44B8:2::2 ! IOS fails to refresh DHCPv6 PD after reconnecting. Workaround: event manager applet MONITOR-IPV6-DHCP-APP event syslog pattern "DIALER-6-BIND" action 1.0 cli command "enable" action 1.1 cli command "clear ipv6 dhcp client Dialer0" action 2.0 syslog priority debugging msg "Refreshed IPv6 DHCP PD lease (Dialer rebind)"
How do I configure an IPv6 firewall on my Cisco router?
Here is a starting point for basic IPv6 Cisco IOS firewall:
ipv6 inspect name STD6 udp ipv6 inspect name STD6 ftp ipv6 inspect name STD6 icmp ipv6 access-list INTERNET-IN-ACL6 permit icmp any any permit tcp any any established permit udp any any eq 546 deny ipv6 any any ipv6 access-list DENY-ACL6 permit icmp any any permit tcp any any established deny ipv6 any any interface Dialer0 ipv6 verify unicast reverse-path ipv6 inspect STD6 out ipv6 traffic-filter INTERNET-IN-ACL6 in interface Vlan1 ipv6 verify unicast reverse-path ipv6 inspect STD6 out ipv6 traffic-filter DENY-ACL6 out
NOTE: There is currently a bug (CSCtb10776) with IPv6 CBAC on Cisco which breaks TCP Window Scaling. Hence the "tcp" inspect module has been omitted and substituted with "permit tcp any any established".
How do I get IPv6 via wireless on a Cisco 877W?
At least IOS 12.4(22)T3 is required to support IPv6 via a wireless Dot11Radio interface
Why don't my hosts get IPv6 addresses when I bridge my WLAN and LAN interfaces?
Cisco does not currently support IPv6 via BVI interfaces. If you use separate routed interfaces (for example, Vlan1 and Dot11Radio0.1) for your LAN and WLAN interfaces it will work.
Why does IPv6 traffic stop working after my PPP session reconnects?
Cisco IOS currently fails to immediately renew the DHCPv6 PD lease after PPP renegotiates. The configuration listed above contains a workaround for this problem. Alternatively, you can force a DHCPv6 PD at any time with the following command: "clear ipv6 dhcp client Dialer0".
Cisco IPv6 Native Ethernet Configuration
Add the following (or similar) to your Cisco router configuration:
ipv6 unicast-routing ipv6 cef ! interface FastEthernet0 description *** Your external network interface *** ipv6 address YOUR-ASSIGNED-IPV6-ADDRESS-FROM-INTERNODE eui-64 ipv6 enable ! ipv6 route ::/0 FastEthernet0
For more assistance on configuring Cisco devices, see:
IPv6 Addressing and Basic Connectivity Configuration Guide (Cisco website)
