[techtalk] Linux and routers

[jennyw]

It may help to know more about your network. The really weird thing about
your description of  your network is that you said that people can get to
the Internet by using either the NAT machine or the router as their gateway.
Does this mean that the NAT machine has a connection to the outside world
that does not go through the router (3)?

By the way, knowing where the DHCP server lives is pretty important. If it's
not on your network (if the router, for example, is forwarding DHCP requests
as in diagram 3), then you could reconfigure the router to not forward DHCP
requests. Instead, you could setup your own DHCP server. Of course, this
would probably make someone angry ...

1:

Internet - NAT - Router --+-- DHCP Server
                          |
                          +-- Workstation1
                          |
                          +-- Workstation2
                          |
                          +-- ...

2:

Internet - Router - NAT --+-- DHCP Server
                          |
                          +-- Workstation1
                          |
                          +-- Workstation2
                          |
                          +-- ...

3:

  Internet       Internet
     |              |
    WAN - Router - NAT --+-- Workstation1
     |                   |
DHCP Server              +-- Workstation2
                         |
                         +-- ...


----- Original Message -----
From: "Kath" <ranger at optonline.net>
To: "Kath" <ranger at optonline.net>
Cc: <techtalk at linuxchix.org>
Sent: Wednesday, April 04, 2001 11:31 AM
Subject: Re: [techtalk] Linux and routers


> I guess I stumped everyone :(
>
>
> - Kath
>
> ----- Original Message -----
> From: "Kath" <ranger at optonline.net>
> To: "James A. Sutherland" <jas88 at cam.ac.uk>
> Cc: <techtalk at linuxchix.org>
> Sent: Tuesday, April 03, 2001 3:05 PM
> Subject: Re: [techtalk] Linux and routers
>
>
> > > Hang on... if this person can't install a tarball, how on earth do you
> > > expect him/her to configure routing properly?!?! Obviously individuals
> > > differ, but I'd have thought routing was a great deal more complex
> > > than installing a tarball...
> >
> > Here is the issue:
> >
> > We have a school web server with an external and internal network card.
> For
> > some reason, noone inside the district can access the web server when
> using
> > straight NAT, but can when using our aging proxy server.
> >
> > Now, if you set the default gateway on any machine in the high school to
> > 10.75.1.4, which is the NAT machine, instead of what the DHCP tells you
is
> > 10.75.1.1 (10.75.1.1 is the router), everything works: internal and
> > external.  However, the grumpy Systems Administrator for the district
> > refuses to change any DHCP server.  He insists that there is no fault
> there
> > and that it is something with the web server.
> >
> > Now, to get to the middle school and elementaries, you have to go
through
> a
> > router, because there is a T1 to each building from the main
distribution
> > point in the high school.  Now my question is, should the default
gateway
> at
> > the elementary/middle schools be the Cisco router for that building (say
> > 10.75.7.1) or should it be the master NAT machine?  Each building has
its
> > own DHCP server, btw, so it is no problem changing it at just one
> building.
> >
> > Now the fellow student I am working with (the one who wouldn't know how
to
> > compile a program) keeps insisting that the problem is in the routes on
> the
> > Linux box and continues to fool around with them, occasionally breaking
> them
> > and then sometimes asking me to fix it, which rather annoys me on the
> > principle of the thing.  Oi vey :|  I've just about given up.
> >
> > Anyway, any ideas on what could be causing this?  I could provide more
> info
> > if I had specific questions...
> >
> > More info:
> >
> > Everytime you plug in www.nbsd.org to a traceroute inside the district,
it
> > gives you the IP of the external card.  The traceroute reveals that it
is
> > dying at/after the 10.75.1.1 router.
> >
> > Now my one hope is that the former consultant to the district, Robert,
can
> > talk some sense into my sysadmin as he is the only one who Gabriel (my
> > sysadmin) will listen to.
> >
> > - Kath the Exasperated
> >
> >
> >
> > ----- Original Message -----
> > From: "James A. Sutherland" <jas88 at cam.ac.uk>
> > To: "Kath" <ranger at optonline.net>
> > Cc: <techtalk at linuxchix.org>
> > Sent: Tuesday, April 03, 2001 2:44 PM
> > Subject: Re: [techtalk] Linux and routers
> >
> >
> > > On Tue, 03 Apr 2001 14:32:53 -0400, you wrote:
> > >
> > > >To my knowledge, the machine does not have any routing protocols on
it.
> > >
> > > It certainly shouldn't be running one at the moment - it's not a
> > > router. Just install the appropriate daemon, and it will be...
> > >
> > > >Still would it share it? (It is Debian 2.2 btw, and if there is no
.deb
> > for
> > > >it, this kid I'm working with would have no idea how to install it
from
> > > >tarball)
> > >
> > > Hang on... if this person can't install a tarball, how on earth do you
> > > expect him/her to configure routing properly?!?! Obviously individuals
> > > differ, but I'd have thought routing was a great deal more complex
> > > than installing a tarball...
> > >
> > >
> > > James.
> > >
> >
> >
> > _______________________________________________
> > techtalk mailing list
> > techtalk at linuxchix.org
> > http://www.linux.org.uk/mailman/listinfo/techtalk
> >
>
>
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