These addresses can't be config on a router?

[weifeng.l]

The following ipv6 address can't be config on a cisco router:

::10.1.1.1/96

::FFFF:10.1.1.1/96

Someone can tell me why?

[Harold Ritter]

The first address is an IPv4 compatible IPv6 address and can therefore not be configured on an interface.

It could be used as a next hop address for a route going over an IPv6 in IPv4 tunnel as follow:

ipv6 route ::/0 ::10.1.1.1

Hope this helps,