Not able to use static route without NAT

[Viktor]

I have Windows 2000 server with five NICs. One of them - 192.168.10.10
is connected to DSL modem and is my connection to the Internet.

DSL modem IP Address is 192.168.10.254.

Other four NICs serve as interfaces to four subnets:

10.10.10.0
10.10.20.0
10.10.30.0
10.10.40.0

I have enabled and configured RRAS on Windows 2000 server.
When I add static route to DSL modem I can't browse Internet from
subnets.
But when I enable NAT I can do that.
I don't want to use NAT on my Windows server because I have it on DSL
modem.

How can configure RRAS not to use NAT and use static route to the
modem?

Thank you.

 

[Bill Grant]

The problem is that your Internet connection is in the 192.168.10.0/24
subnet. So it is only aware of that subnet. If you enable NAT on the server,
all traffic going out to the Internet uses the server's 192.168.10.10 IP as
the return address, so the DSL router will forward the traffic to the
server. Without NAT, it will not forward traffic for the other subnets,
because it has no routing information to tell it where they are!

To route the other subnets to the Internet without NAT on the W2k server,
your Internet router must know how to route traffic for the "internal"
subnets. You could use RIP (if the DSL router supports it), or you can use
static routing, or you can use subnetting.

For RIP, you would enable RIP in the Internet router's internal
interface and the server's "external" interface (ie the interfaces in the
192.168.10 subnet). The Internet router would then "learn" routes to the
internal subnet via the RRAS router.

For a static routing solution, you would add static route (or routes)
for the internal subnets. eg

192.168.0.0 255.255.0.0 192.168.10.10

or you could add a separate route for each subnet if you don't like that
method.

For the subnetting solution, you make the "public" dummy subnet
192.168.0.0/16 instead of 192.168.10.0/24. Then all machines inside the DSL
router are covered by its netmask, and traffic will be forwarded to the RRAS
server. It has the same effect as adding the 192.168.0.0 255.255.0.0
static route.

 

[Viktor]

How do I make changes to DSL router. I don't have access to it. Should
I call my ISP? I am not sure they would like to do that.

 

[Bill Grant]

You may be right about that, but there is really no alternative. You
cannot fix this problem by making changes anywhere else.

The DSL router somehow must be made aware of the other internal subnets,
one way or another. Otherwise it will never forward the packets on.

How many machines are in each subnet? If there are only a few, you could
further subnet the 192.168.10 subnet for the internal segments. So instead
of using 10.10 addresses, you could use 192.168.10.x/26 (ie 26 bit subnet or
255.255.255.192) . That would give you four internal subnets with up to 62
clients in each. (192.168.10.0/26, 192.168.10.64/26, 192.168.10.128/26 and
192.168.10.192/26 ). Its a fair bit of work, but it is the only way to do
it
without changes at the DSL router.

PS. Sorry I misread your internal IP addresses previously. The static route
you would need on the DSL router is, of course, this

10.10.0.0 255.255.0.0 192.168.10.10