[IPv6]Re: [v6ops] Re: New draft: "The IPv6 Loopback Address Prefix"

[Brian E Carpenter <[e-mail]>]

On 26-Nov-25 18:52, Owen DeLong wrote:
> 
>> By the way, there is a difference between IPv4 and IPv6 that the draft doesn't mention. IPv4 addresses are assigned to the host. IPv6 addresses are assigned to a specific interface. There's a virtual loopback interface in IPv6 implementations, which presumably will "own" the whole proposed /96. That should be mentioned.
> 
> What are you talking about, Brian?

The formal definitions. RFC 8200  defines "address" as "an IPv6-layer identifier for an interface or a set of                  interfaces" (as did RFC 2460 and RFC 1883). RFC 791 says "... where sources and destinations are hosts identified by fixed length addresses."

Admittedly, RFC 791 is inconsistent since it also says "... provision must be made for a host to have several physical interfaces to the network with each having several logical internet addresses." Your observation about DHCPv4 is probably a side effect of that inconsistency.

I don't mean this has any profound effect.

     Brian

> 
> All of my interfaces on Linux, BSD, MacOS, JunOS, and any other platform I’ve encountered have assigned both v4 abd v6 addresses to the individual interface and not the host.  While it’s true that there is some ambiguity in this regard for DCHPv4, the end result is still that the assigned address ends up assigned to a specific interface and not the entire host.
> 
> Owen
> 
>