execute : ping6
 
ping6
Send an ICMP echo request (ping) to test the network connection between the FortiGate unit and an IPv6 capable network device.
Syntax
execute ping6 {<address_ipv6> | <host-name_str>}
Example
This example shows how to ping a host with the IPv6 address 12AB:0:0:CD30:123:4567:89AB:CDEF.
execute ping6 12AB:0:0:CD30:123:4567:89AB:CDEF