Subject: Re: Why netmask 255.255.255.255 is needed for PPP
To: None <current-users@NetBSD.ORG>
From: Peter Seebach <firstname.lastname@example.org>
Date: 11/22/1996 08:51:30
>Some other UN*X clones let you do this, I hear. I would like to have that
>option, too. I know everything can be done without it, but it would be
>much easier for a human being to specify routes by interface names, not IP
Perhaps my understanding is incomplete; I am unable to specify routes
correctly by IP address alone. Why? Because PPP links that don't have a
netmask of 255.255.255.255 grab any route that comes near them.
(There's an unrelated problem we used to have where a dropped PPP link would
go to a target of "0.0.0.0" and grab any route whatsoever, no matter what it
was aimed at, but that seems to have gone away.)
Mostly, I would like to be able to enfore that a route for a machine on my
ethernet is done via le0, no matter *what* other interfaces look (to whoever
guesses) to be relevant, because it guesses wrong...
It wouldn't hurt to see if we can figure out why a PPP link to
220.127.116.11, netmask defaulted to 255.255.255.240, is chosen as the default
target for a route to 18.104.22.168, when that's clearly in the range of the
My problem may be related to having my end of every PPP or SLIP connection
have the same IP as le0, but I thought that was okay, and it is, apart from
routing strangeness wihch goes away if you ifconfig ppp interfaces to netmask
Which brings us full circle; why does "netmask 255.255.255.255" in the options
file not work?