Subject: Re: illegal network routes and a ponderance
To: None <>
From: David Young <>
List: tech-net
Date: 02/19/2003 22:51:44
On Wed, Feb 19, 2003 at 07:11:56PM -0500, der Mouse wrote:
> >> Yes, I ran into this myself, and hacked on the ARP code to make ARP
> >> entries interface-specific.  The result has some problems [...]
> > I think if you satisfy the following:
> > . Default is to publish on all interfaces.
> > . If an interface is specified, publish only on that interface
> > ... then I say clean it up and submit it.
> It doesn't.  It makes ARP entries interface-specific.  If you want to
> publish on all interfaces, you have to add N ARP entries, and you can't
> actually do that because ARP entries are actually host routes with the
> LLINFO flag set, and you can't have multiple distinct routes with the
> same destination.

*snip snip*

> The Jargon File entry for "uninteresting" says, in part,
>                                                Real hackers (see
>    toolsmith) generalize uninteresting problems enough to make them
>    interesting and solve them -- thus solving the original problem as a
>    special case

  Speaking of *interesting* problems, it is an interesting problem
  that in NetBSD you CANNOT have multiple distinct routes with the same
  destination. This has unexpected effects in wireless networks, where
  sometimes it is desirable to keep a remote route to a host for the
  purposes of IP traffic, but also to keep a link-local route to the
  same host for the purpose of route set-up and discovery.

  Excuse me for plugging my pet bug in NetBSD. =)


David Young             OJC Technologies      Engineering from the Right Brain
                        Urbana, IL * (217) 278-3933