> Finally, the reasons for not peeking at the actual > link layer addresses used in the link layer frame can > be summarized as follows: > > 6. Separation of function > > This again follows the architectural principle. > Especially, it was viewed that checking the > link-layer addresses is a link layer function, > and it should be separate from the IP layer. > > Is that all or am I missing something? Or is there > something above that doesn't belong there?
I recall there was also a feeling that since ARP provides the same separation (ARP doesn't use the addresses in the link-layer frame) it would be a bit too creative to remove it. I think the separation in ARP has, if not helped, given more flexibility e.g. when bridging between different 802 media with different bit order in the header (e.g. Ethernet to Token ring or FDDI). Also, I think it might have helped for media that doesn't have actual link-layer addresses but instead just a local DLCI - where the DLCIs each end sees is different. In that case there isn't an address in the datalink header you can use. Erik -------------------------------------------------------------------- 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] --------------------------------------------------------------------
