Can someone explain this to me, I found it doesn't go away even if I switch from a /64 on say 1873 to 1875 etc. Randomly it goes away or this issue spreads.

I am about as stupid as it gets to IPv6 on MikroTik, so any help is appreciated.

My ISP gives me a /60 if that helps.

@archerious Did you get any answers on this - it's making our routers unusable.

The fix for (horrific IPv6 issues) on RouterOS was to disable and re-enable all IPv6 addresses at startup - but that doesn't seem to resolve this specific issue.

Have you tried to enable 'EUI-64' in address? Maybe another device is trying to use the same address (prefix obtained with all the other bits 0). If you construct your IP address using the prefix + EUI-64 you shouldn't have this problem

Have you tried to enable 'EUI-64' in address? Maybe another device is trying to use the same address (prefix obtained with all the other bits 0). If you construct your IP address using the prefix + EUI-64 you shouldn't have this problem

That fixed it! I don't see any other devices using the exact prefix, but enabling EUI64 resolved it!

Do you have a donation link? This saved me so much, god bless you!

> Maybe another device is trying to use the same address (prefix obtained with all the other bits 0)

It happens very easily on Linux network stack. If Linux considers itself a router (which is the same as having "forwarding" enabled), it will claim the all-zeros address, EDIT: even though it will never explicitly appear in . If you have VMs, Docker containers, etc., you will automatically have forwarding turned on.

As things are now, trying to suppress this behaviour is an exercise in futility.

This issue started happening again sadly.

I had the same problem and the v6addr became invalid.
This was confirmed in RB4011 7.1rc6 and 7.1stable.

A temporary workaround was to shutdown all I/F on the router except the WAN, enable/add the address, and then enable the interfaces.
This would allow the v6 address to be used, but once the router rebooted, the address would be disabled again.

I think the problem is that it happens even if I set the "No DAD" option for the address.

I just hit this issue on an RB750gr3 running v7.8

@jprietove's fix of enabling eui64 has resolved it.