Date: Sun, 4 Jan 1998 11:05:21 +0100 From: J Wunsch <j@uriah.heep.sax.de> To: Greg Lehey <grog@lemis.com> Cc: Brian Somers <brian@awfulhak.org>, John-Mark Gurney <gurney_j@efn.org>, freebsd-bugs@hub.freebsd.org, freebsd-hackers@FreeBSD.ORG Subject: Re: kern/5404: slXX slip (tun & ppp) interfaces always point to point Message-ID: <19980104110521.14399@uriah.heep.sax.de> In-Reply-To: <19980104174838.41538@lemis.com>; from Greg Lehey on Sun, Jan 04, 1998 at 05:48:38PM %2B1030 References: <199801010130.RAA10049@hub.freebsd.org> <199801011325.NAA17803@awfulhak.demon.co.uk> <19980102105504.61189@lemis.com> <19980102102027.41384@uriah.heep.sax.de> <19980104174838.41538@lemis.com>
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As Greg Lehey wrote:
> I had a discussion about this with a bloke here in Adelaide a couple
> of months ago. He runs a large ISP, and he came up with some
> plausible reason, but unfortunately I've forgotten the details. It
> had to do with Microslop: they use broadcasts a lot, and this would
abuse :)
> seem to indicate that they expected broadcasts on a /26 subnet, or at
> least were prepared to respond to them.
So this netmask crap might apply for M$ then -- they still have a long
way to be internet-ready. For us, an interface is either
IFF_BROADCAST, or IFF_POINTOPOINT, but not both. Thus, the netmask
and broadcast addresses of a p2p interface are irrelevant. (If you
think about it, both, broadcasting and p2p are mutually exclusive by
logic. p2p is always unicasting to just one peer.)
> It sounds like you're saying that PPP shouldn't be allowed to set the
> default route automatically when the link comes up.
No, i was really telling that there should be _only_ the implied host
route automatically installed when upping a p2p interface, but no
other route. ISTR Brian suggested a second route should be derived
from the (bogus) netmask, and installed {too or instead}. So per
Brian's suggestion:
ifconfig foobar0 1.2.3.4 1.4.5.6 netmask 0xffffff00
would have implied
route add 1.4.5.6 -iface foobar0
route add -net 1.4.5.0 -netmask 0xffffff00 1.4.5.6
while the existing behaviour (and what i think is the Right Thing) is
only the first of both routes.
Installing a default route is always done separately anyway.
--
cheers, J"org
joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)
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