Pekka Savola wrote: > > I hope you're not implying that apps should know the difference between > the two? That would be broken. The host probably could, though.
In most situations, an application would not be required to know the difference between the addresses, relying on correct behaviour of gethostbyname (destination address selection) and source address selection. However, certain applications may wish to deliberately operate at a certain scope (such as those doing ip address referrals between hosts which have local and global addresses and those which only have global addresses) and these would need to override the default address selection rules, thus being conscious of address scoping. > I think a better method would be to give preference to global unicast, > ie., reverse the scoping rule to prefer the greatest scope. On what grounds? Local scoped addresses are not mandatory, and thus should only be put in place if they are intended to be used. To my way of thinking, the presence of a locally scoped address suggests that the network is unwilling to trust the global address for local communication, and would thus expect the local address to be preferred for local-local traffic. > > However it is useful if a host can have both types of addresses > > and use them appropriately. This creates a host with multiple global > > addresses, a form of multihoming. > > I fail to see how a local and a global address could be considered a form > of multihoming. It depends on your definition of multi-homing. I've hear the term used in the following ways: - A network with access to the global internet via more than one independent path. - A node with more than one usable address (having addresses in more than one logical subnet simultaneously). The second definition is being referred to above. -- Andrew White [EMAIL PROTECTED] -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
