IPv6

IPv6 Configuration

1. To prepare for a migration to IPv6, enable IPv6 routing and configure IPv6 addresses on R1, CSW1, and CSW2: a. R1 G0/0/0: 2001:db8:a::2/64
   b. R1 G0/1/0: 2001:db8:b::2/64
   c. R1 G0/0 and CSW1 G1/0/1: Use prefix 2001:db8:a1::/64 and EUI-64 to generate an interface ID for each interface.
   d. R1 G0/1 and CSW2 G1/0/1: Use prefix 2001:db8:a2::/64 and EUI-64 to generate an interface ID for each interface.
   e. CSW1 Po1 and CSW2 Po1: Enable IPv6 without using the ‘ipv6 address’ command.

Configure IPv6 Unicast Routing:

R1(config)#ipv6 unicast-routing

Configure R1s Internet facing interfaces:

R1(config)#int g0/0/0
R1(config-if)#ipv6 address 2001:db8:a::2/64
R1(config-if)#int g0/1/0
R1(config-if)#ipv6 address 2001:db8:b::2/64

Configure R1s LAN facing interfaces (EUI-64 automatically generates Interface IDs):

R1(config-if)#int g0/0
R1(config-if)#ipv6 add 2001:db8:a1::/64 eui-64
R1(config-if)#int g0/1
R1(config-if)#ipv6 add 2001:db8:a2::/64 eui-64

Confirm with:

R1(config-if)#do sh ipv6 int br
GigabitEthernet0/0         [up/up]
    FE80::20C:CFFF:FE08:5001
    2001:DB8:A1:0:20C:CFFF:FE08:5001
GigabitEthernet0/1         [up/up]
    FE80::20C:CFFF:FE08:5002
    2001:DB8:A2:0:20C:CFFF:FE08:5002
GigabitEthernet0/2         [administratively down/down]
    unassigned
GigabitEthernet0/0/0       [up/up]
    FE80::2E0:A3FF:FE95:4D4E
    2001:DB8:A::2
GigabitEthernet0/1/0       [up/up]
    FE80::2E0:F7FF:FE68:6426
    2001:DB8:B::2

Above shows the four interfaces configured, each with a link-local address as well as the global unicast address we configured.

Configure CSW1 and CSW2:

CSW1(config)#ipv6 unicast-routing
CSW1(config)#int g1/0/1
CSW1(config-if)#ipv6 add 2001:db8:a1::/64 eui-64

CSW2(config)#ipv6 unicast-routing 
CSW2(config)#int g1/0/1
CSW2(config-if)#ipv6 add 2001:db8:a2::/64 eui-64

Finally, do the EtherChannel between CSW1 and CSW2. Enabling IPv6 on the PortChannel automatically generates a link-local address:

CSW2(config-if)#int po1
CSW2(config-if)#ipv6 enable
CSW2(config-if)#do sh ipv6 int br
Port-channel1              [up/up]
    FE80::230:F2FF:FEEC:2B09
GigabitEthernet1/0/1       [up/up]
    FE80::2E0:B0FF:FE5C:7E01
    2001:DB8:A2:0:2E0:B0FF:FE5C:7E01
GigabitEthernet1/0/2       [up/up]
    unassigned
GigabitEthernet1/0/3       [up/up]
    unassigned

Configure CSW1:

CSW1(config-if)#int po1
CSW1(config-if)#ipv6 enable

1. Configure two default static routes on R1:
   a. A recursive route via next hop 2001:db8:a::1.
   b. A fully-specified route via next hop 2001:db8:b::1. Make it a floating route by configuring the AD 1 higher than default.

R1(config)#ipv6 route ::/0 2001:db8:a::1
R1(config)#ipv6 route ::/0 g0/1/0 2001:db8:b::1 2