The ipv6 security permit incomplete-first-fragment command enables the function not to check the packets with an incomplete first fragment header.
The undo ipv6 security permit incomplete-first-fragment command disables the function not to check the packets with an incomplete first fragment header.
By default, the function not to check the packets with an incomplete first fragment header is disabled.
Usage Scenario
If a router needs to process IPv6 packets with an incomplete first fragment header, the capability of receiving such packets must be reserved. To enable the function not to check the packets with an incomplete first fragment header, run the ipv6 security permit incomplete-first-fragment command.