Subject: Re: Beginner questions
To: None <marsmail@globegate.utm.edu>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 05/19/1997 13:51:26
> 
> On Fri, 16 May 1997, Jesse Swensen wrote:
> 
> > internet gateway for the 2-3 other machines on my little network.  There is
> > a port in progress for a 68k version of linux.  I would like that.  There
> > seems to be a lot more information about linux.
> 
> You'd be surprised.  There's a lot left to be documented about linux....
> Where NetBSD, you just pick up a copy of Nemeth, Seebass, et al... Unix
> System Administration... the red book.

Plus there's the difference between Slackware, Redhat, and others.
Configuring the system depends on the support programs as much as
the kernel.

>                                         Network config seems to be
> somewhere between bsdi and solaris.  For hostname.ae0, try
> 
> inet myhostname 0xff000000 10.0.0.n
> 
> or tweak the netmask as desired (technically, I think 10.'s should be
> class A, and thus have a netmask of 0xff000000). re

I'm confused. The above line makes no sense to me. What is the 10.0.0.n
supposed to be? The broadcast address?

If it's the broadcast address, it's wrong.

About netmasks, a Class A's _outside_ your own are netmask 0xff000000
as that's the point (everything that matches gets thrown to one
foreign router which deals). But YOUR OWN Class A can have whatever
netmask you want. Just everyone must agree.

I run my little home net w/ 0xffff0000 as the netmask. As all machines
have the same setting, it's ok.

For now, if the broadcast address is the "standard" for your netmask,
just leave it off. I don't think you can set it under MacOS, so you're
living with the default...

The default is you just have 1's in the space not in the netmask.
So for 10.X.X.X, netmask 0xff000000, the broadcast address is
10.255.255.255. 10.0.0.255 would be right with a netmask of 0xffffff00.

> > Internet:
> > Destination		Gateway		Flags	...	Interface
> > 10.0.0.3		127.0.0.1	UGHS		lo0 =>
> > 10.0.0.3		link#1		UC		ae0
> > 10.0.0.255		link#1		UHL		ae0
> > 127.0.0.1		127.0.0.1	UH		lo0
> 
> gateway link#1??  Your box is 10.0.0.3, right?  You should add a default
> route to everything else on ae0.  Something like
> 
> route add default 10.0.0.3
> 
> with maybe a "-interface ae0" in there somewhere.
> 
> and maybe ditch the route from 10.0.0.3 to localhost.  That should be
> implied as long as the interface is up (which it appears to be).

???? You should only use "default" to point to a router. You should NOT
use it to point to one of your network addresses. A network address
with a netmask will generate a route to everything on that net.

Since you've mentioned using this box as a gateway (which it should
be able to do), you'll either need to get real IP addresses for
everything (10.X.X.X won't do as the other folks can't talk to it),
or run the firewall toolkit (a form of masquerading).

If you use the real IP approach, make the default route on the other
machines point to the modem'd computer, and then have the modem'd
computer's default route point to the other end of the ppp or slip
link. If you go the masquerading way, you don't need a default
route as the only computers you can directly talk to are on your
local net.

Take care,

Bill