Technical Tip: How to verify an IPv6 link-local address (LLA) connectivity

[alif]

Description
This article describes how to verify IPv6 connectivity.

Solution
The first step is to configure an IPv6 address on an interface.

# config system interface
    edit "wan1"
        set vdom "root"
        set type physical
        config ipv6
            set ip6-address 2003:de:2016:210::1/64
            set ip6-allowaccess ping https ssh            
        end
    next
end

# diagnose ipv6 address list

dev=5 devname=wan1 flag=P scope=0 prefix=64 addr=2003:de:2016:210::1 preferred=4294967295 valid=4294967295 cstamp=290729 tstamp=290729
dev=5 devname=wan1 flag=P scope=253 prefix=64 addr=fe80::926c:acff:fee5:4c50 preferred=4294967295 valid=4294967295 cstamp=290729 tstamp=290729

The following IPv6 address is configured on the Windows machine.
IPv6 Address. . . . . . . . . . . : 2001:aa:bb:cc::101(Preferred)
Link-local IPv6 Address . . . . . : fe80::598:2d42:a930:fbc8(Preferred)

In order to send an ICMP echo from the FortiGate link-local address (LLA) to Windows LLA, the following command is used from CLI.

# execute ping6 fe80::598:2d42:a930:fbc8 -I wan1
PING fe80::598:2d42:a930:fbc8(fe80::598:2d42:a930:fbc8) from fe80::926c:acff:fee5:4c50 wan1: 56 data bytes
64 bytes from fe80::598:2d42:a930:fbc8: icmp_seq=1 ttl=128 time=0.571 ms
64 bytes from fe80::598:2d42:a930:fbc8: icmp_seq=2 ttl=128 time=0.414 ms
64 bytes from fe80::598:2d42:a930:fbc8: icmp_seq=3 ttl=128 time=0.542 ms
64 bytes from fe80::598:2d42:a930:fbc8: icmp_seq=4 ttl=128 time=0.248 ms
64 bytes from fe80::598:2d42:a930:fbc8: icmp_seq=5 ttl=128 time=0.839 ms

The following arguments are available on the FortiGate for IPv6 which are similar to general Linux in this example.

Usage: ping -6 [-aAbBdDfhLnOqrRUvV] [-c count] [-i interval] [-I interface]
[-l preload] [-m mark] [-M pmtudisc_option]
[-N nodeinfo_option] [-p pattern] [-Q tclass] [-s packetsize]
[-S sndbuf] [-t ttl] [-T timestamp_option] [-w deadline]
[-W timeout] destination