On Tue, Oct 12, 1999 at 01:57:39PM -0400, Matthew N. Dodd wrote:
> On Fri, 8 Oct 1999, Thor Lancelot Simon wrote:
> > BSD basically doesn't *have* an abstract layer for link-layer
> > processing and when you start to look at things like PPPoE or VLANs or
> > EtherChannel it really shows.
> 
> Also once could do multipath routing, MAC address takeover etc.
> 
> I'm interested in this from the FreeBSD POV and have been thinking that a
> solution that abstracts the current interfaces away from the hardware
> driver would be the way to go.
> 
> IPv4, IPv6, Appletalk, IPX, ISO ...
> ----------------------------------------------------
> MAC Framing Layer	ethernet_II, 802.3, HDLC ...
> Network Interface	eth, tok, fddi, sppp ...

This layer seems superfluous to me.  Where is there a win over simply
collapsing your "MAC Framing Layer" and "Network Interface" into a
"link layer protocol"?

> Hardware Interface	de, fxp, xl ...

I'm with you here.

I believe that if_media with some extensions is flexible enough to
allow all the relevant options to be set, if you've got multiple layers
to work on.  This appeared to be the case when I was working on 
multiprotocol sync serial stuff and thinking about EtherChannel.