[CentOS] what wrong about my ipv6 address

Hi 

I used the command "ip -6 addr add 2001:DB8:CAFE:1111::12/64 dev eth0"

to add ipv6 address and can see it in ifconfig 

but can't ping it

Why?

Thank you

# ping6 2001:db8:cafe:1111::12
PING 2001:db8:cafe:1111::12(2001:db8:cafe:1111::12) 56 data bytes
>From ::1 icmp_seq=1 Destination unreachable: Address unreachable
>From ::1 icmp_seq=2 Destination unreachable: Address unreachable
>From ::1 icmp_seq=3 Destination unreachable: Address unreachable
>From ::1 icmp_seq=5 Destination unreachable: Address unreachable
>From ::1 icmp_seq=6 Destination unreachable: Address unreachable
>From ::1 icmp_seq=7 Destination unreachable: Address unreachable
>From ::1 icmp_seq=9 Destination unreachable: Address unreachable
>From ::1 icmp_seq=10 Destination unreachable: Address unreachable
>From ::1 icmp_seq=11 Destination unreachable: Address unreachable