On 5-jul-04, at 17:41, Christian Huitema wrote:
but it definitely is a problem for *host* multihoming, e.g. a host with a WiFi and a GPRS connection.
So what about a solution like NOID where this information is in the DNS?
I don't understand why you find it objectionable that someone would see which two IP addresses belong to the same host. I mean, what does this tell the third party?
As I understand it, the reason that RFC 3041 exists is because having a MAC-derived IP address allows a third party to follow a host's movement from one link to another. I can see why people wouldn't want that to happen. But I don't see how disclosure of a fixed relationship between two addresses or prefixes is similar. That is, unless multihoming is combined with some sort of mobility.
Come to think of it, the only way to not disclose these relations to third parties is to (1) make sure that the identifier is not disclosed as part of the IPv6 address and (2) make sure that the identifier is only exchanged over an encrypted channel between the corresponding hosts.
But you pretty much always need to inform the correspondent, and an attacker who can snoop a link will often be in the position to become a correspondent and thus learn the information. If there is no snooping there is no reason for encryption.
Also, in the case of referrals, disclosure to a third party is necessary and desirable. In any case, the current state of the Internet is that IP addresses are public knowledge, and we are not under any obligation to change that as part of multi6.