Using IPv6 link-local addresses to ping between VMs in internal VirtualBox network

Question

I'd like to test this network configuration in fully virtualized enviroment, while I don't have access to physical lab.

I am using 2 VM Guest machines (Guest OS is Archlinux), each configured with NAT adapter and one internal network adapter. Pinging between these machines on IPv4 using internal adapter addresses is no problem.

I would like to set up link-local addresses on internal interfaces and use ping6 to test out reachability:

VM1: fe80::1:1/64
VM2: fe80::1:2/64

From my understanding, this should work no problem when these two hosts would be connected to same physical switch right? However, after using

ping6 -I enp0s8 fe80::1:1/64

I only get

unknown host

Is this problem only VirtualBox specific and should work on real machines or is something wrong with my assumptions on how IPv6 link-local addresses work?

Answer 1

The real address is fe80::1:1, or fe80::1:1%enp0s8 with the scope identifier.

Prefix length (the /64) is only used when configuring the interface and is not part of the address. It is equivalent to the "subnet mask", and you don't give the subnet mask to ping either, do you?