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Is an ICMPv6 neighbor advertisement meaningful if no options are set?

        This is what I think a normal ICMPv6 neighbor advertisement should look like:
Wireshark screenshot of an ICMPv6 neighbor solicitation with option 2 (target link-layer address) set to a mac address It says "I'm 2001:57a:d000::54 and you can reach me at 02:02:53:85:21:25". This is what neighbor advertisements from my ISP look like. By contrast, this is what neighbor advertisements from my Fortigate router/firewall look like: Wireshark screenshot of an ICMPv6 neighbor solicitation with no options set Notably, this does not include the Fortigate's mac address. I suppose the other end could figure it out based on the Ethernet header. Is this how it's supposed to work? My issue is that the Fortigate can send packets, but can't receive them. I am suspicious it is because my gateway is Neighbor Solicitation-ing to try to get a mac address to send return packets to, but it is getting an empty reply.

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