for some reason fe80::21/64 has been a pain in the a** for me, another mikrotik also loves to use it as a local address on a vpn, i do not know how to tell them “please, not, use this instead”
So, basically between the master mikrotik and this specific mikrotik there can be no IPv6 connectivity because the Local address on Mk1/VPN is the same as in Mk2/VPN2… if this is not clear, let me put it this way:
Mikrotik 1 —> Mikrotik 2 share a VPN on which they have Mk1 Local Adress as fe80::21 and Mk2 as fe80::22, then Mk2 has another vpn on which the Mk2 uses as local address fe80::21 and as remote fe80::23, and now there’s an ip conflict.
This issue is on v6.49.3
This is one of the problems i have on ipv6 the second major problem is that i can’t figure out how to hand out Prefixes on dhcpv6 (i have a /48 prefix delegated)
It is nothing to do with the user configuration or global unicast (GUA) / unique local (ULA) addresses. Whilst Mikrotik generate EUI-64 based link-local addresses from the EUI-48 MAC address on interfaces, they only do so for interfaces which have a MAC address, and appear to use the internal interface index for those which do not. The only way to change these is to delete the interface and create a new one which will use the next free internal ID.