Stymied on a PPTP Routing Question

[Sandy Green]

hi mike,

the two networks your 10..x.x.x and 172.x.x.x are
connected via a leased or a private line and not the
internet.  right ... ?

and there is complete IP connectivity between the
two networks via routes... fine

next you connect to your 10.x.x.x network via PPTP
from home. Your home computer already had a routable
IP address and you extablish a PPTP tunnel to one
of your PPTP servers sitting at the edge of your
10.x.x.x network. This PPTP server is dual home host.
ie it has two NICs. one of the NIC is a 10..x.x.x
address
and the other NIC is facing the internet and has a
class C or a routable IP address with which you
connect
your home computer to. right .... ? did i get your
environment right ??

if i get this right then i do not think that you would
be
able to connect to any 172..x.x.x network. because
the PPTP server is the gateway that is sitting
between your home computer and the 10..x.x.x network.
ie the tunnel is fine between your home computer and
the 10.x.x.x. network.... remember that the 10..x.x.x
IP addresses are the tunnelled in ones. once the
tunnel is bared ie the PPTP packets are stripped off
and the tunnlled IP packets bared they are going to
arp to reach their destinations.... since they are
arping
they would not be able to cross a router.

hence if you want to reach a 172 network from your
home computer via PPTP then
necessary route is to be  put at the PPTP server
which is in your 10.x.x.x network. i don' think that
can be achieved though.

The only way you can do is to have a PPTP server
set up at your 172.x.x.x network and dial into it to
access hosts in the 172.x.x.x network from your home
computer.

list members please comment .... because i too had
a similar evironment..

thanks
sandy



--- Michael Medwid <Michael.Medwid at ARIBA.COM> wrote:
> Currently our internal address space at our company
> is 10.x.x.x.  We recently acquired a company whose
internal address space is 172.2.x.x.
> Their routes have populated our routers via eigrp
> and from my 10.x.x.x network I can ping or telnet
any device on the 172.2 network.  However if I
> use PPTP to tunnel into our network from my home
> system on DSL (with a routable IP address) I can get
to any system on the 10.x.x.x subnet but I can not
reach anything on the 172.2.  I tried manually adding
routes while the PPTP tunnel was up.  That did not
help. Can you think of what might be limiting my
access to only the 10.x.x.x network?
> Any solutions?  If this question is too specific for
this mail list send me a whack on the head.  :-)
>
> -Michael

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