Configure IPv6 forwarding. By default, IPv6 forwarding is globally disabled, which means you can only use local IPv6 connections, and traffic does not traverse an IPv6 network.
default ipv6 forwarding
ipv6 forwarding
no ipv6 forwarding
By default, forwarding is enabled on an interface. You must enable it globally before the interface configuration takes effect.
GigabitEthernet Interface Configuration