Hardware Tunnel Support
The platforms and software versions that provide hardware forwarding support for IPv6 traffic for both IPv6-in-IPv4 and 6to4 tunnels for various platforms are shown in the following table. In all the other platforms, tunnel traffic is forwarded in software and the statistics can be viewed from the show ipstats ipv6 command.
The MTU for IPv6 Tunnels is set to 1480 bytes, and is not user-configurable. Configuring jumbo frames has no effect on the MTU size for IPv6 tunnels.