Platonides wrote:
Thomas Dalton wrote:
This doesn't help ID the person (MAC tells you manufacturer, and sometimes model, but that's all). But it does help for blocking...
It helps to confirm that two people are the same. While a checkuser that shows that two accounts are being used by people with the same ISP would at best be a "likely", a checkuser that shows two accounts are being accessed via the same network card would be a definite match (assuming the rest of the address rules out a public computer).
On today's OS it's easy to change the PC's MAC. No doubt vandals will learn it fast. Even worse, if we treat as one-MAC one-user, and block by it, a vandal can vandalise with the mac of a legitimate user (one unlogged edition is enough to disclose it), which will found themselves blocked and appear as they were the vandal.
I'm not sure there's anything in the IPv6 specs to mandate the use of MAC addresses for assigning host parts: it's just one easy way to do it in a stateless way, but since it would expose the make and exact serial number of your network adapter (which is most likely built into your motherboard, these days), it's also a giant privacy hole.
I think ISPs are much more likely to allocate the host part of IPv6 addresses either dynamically (and to keep logs), or to allocate a single static IPv6 address per account.
Presumably, for a customer who wants to expose multiple IPv6 addresses, they would do something like allocate a /64 to each user, and let them pick their own host parts, perhaps using DHCPv6, which would then necessarily have anything to do with the actual MAC address of the hosts' own network adapters.
-- Neil