Subject: Re: your recent ARP changes...
To: Matt Thomas <>
From: Fred L. Templin <>
List: tech-net
Date: 04/21/1997 09:36:10

> I do understand (I sent my own flame over a month ago about this very
> subject).  But I adapted because the fundamental thing was that 4.*BSD
> was broken (and has been).  Just as not all the world is a VAX, not all
> network interfaces are Ethernet.  

Thanks for the clarification. I agree (as I pointed out in my earlier
messages), that 4.*BSD has been broken since the beginning of time when
the original developers chose to marry the Ethernet and ARP data structures
in a single file (if_ether.h), and then placed that file in a directory
associated with the network and transport layer protocols (netinet), rather
than the datalink layer (net) as it should have been. But fixing things now
in NetBSD will only make NetBSD appear to be broken w.r.t. the other 4.*BSD
systems. (i.e. You can't globally erase ~15 years of broken history by fixing
things locally.)

> I would like to have backwards compatibility but sometimes it makes things
> even uglier.

I think having a generic "arpcom" data structure with pointers off to the
datalink-specific data structures would be a workable compromise which would
allow backwards compatibility as well as flexibility to support heterogeneous
datalinks now and into the future.

> -- 
> Matt Thomas               Internet:
> 3am Software Foundry      WWW URL:
> Westford, MA              Disclaimer: I disavow all knowledge of this message