IPv6's interface ID

johnifanx98

I read "MAC addresses are considered to be uniquely assigned worldwide" so interface ID can be generated from the MAC. But is this assumption correct?

clarson

yes that is right. but, it is wrong to make that assumption, as interfaces can be assigned a non burned in mac address. and, also be given an ip address not based on it's mac address

So, the first thing an interface does after generating a ipv6 address from it's burned in mac address is to send out an advertisement to see if that ipv6 address is already in use. If it isn't already in use, the interface will use it.

so it is generate and verify. not generate and assume.