Routing table question.

I have a point to point T1 anchored at each end with a Cisco 1720
Router. I also have a T1 line that goes to the internet. The servers
at either end have 2 NIC's each.

Site #1 looks like this:

Internet NIC:
ip 192.168.0.100
mask 255.255.255.0
gateway 192.168.0.1

Point to Point NIC:
ip 10.2.0.4
mask 255.255.255.0
I didn't put a gateway here because I found it caused more problems
and didn't solve any.

Point to Point routers
Site 1: 10.2.0.2 -> 10.0.0.1 -> Site 2: 10.0.0.2 ->10.1.0.2

Site #2 is set up like this.

Internet NIC:
192.168.50.2
255.255.255.0
192.168.50.1

Point to Point NIC
10.1.0.4
255.255.255.0

I know I need to make an entry into the routing tables to make the
point to point traffic use only the 10...etc NIC, but I'm not sure
about the syntax. Any help would be appreciated.

Correct, you should not add default gateway in 10 LAN. However, you do need to add route to point to other site, for example route add 10.1.0.0 mask 255.255.255.0 10.2.0.2. More details can be found this link.

RoutingAnalysis 1: before changing the route table, any computers in 192.168.2.0 can access the resources on 10.0.0.0 network and the Internet because all traffic ...
www.chicagotech.net/routing.htm


Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com
<(E-Mail Removed)> wrote in message news:(E-Mail Removed) ups.com...
I have a point to point T1 anchored at each end with a Cisco 1720
Router. I also have a T1 line that goes to the internet. The servers
at either end have 2 NIC's each.

Site #1 looks like this:

Internet NIC:
ip 192.168.0.100
mask 255.255.255.0
gateway 192.168.0.1

Point to Point NIC:
ip 10.2.0.4
mask 255.255.255.0
I didn't put a gateway here because I found it caused more problems
and didn't solve any.

Point to Point routers
Site 1: 10.2.0.2 -> 10.0.0.1 -> Site 2: 10.0.0.2 ->10.1.0.2

Site #2 is set up like this.

Internet NIC:
192.168.50.2
255.255.255.0
192.168.50.1

Point to Point NIC
10.1.0.4
255.255.255.0

I know I need to make an entry into the routing tables to make the
point to point traffic use only the 10...etc NIC, but I'm not sure
about the syntax. Any help would be appreciated.

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ups.com...
>I have a point to point T1 anchored at each end with a Cisco 1720
> Router. I also have a T1 line that goes to the internet. The servers
> at either end have 2 NIC's each.
>
> Site #1 looks like this:
>
> Internet NIC:
> ip 192.168.0.100
> mask 255.255.255.0
> gateway 192.168.0.1
>
> Point to Point NIC:
> ip 10.2.0.4
> mask 255.255.255.0
> I didn't put a gateway here because I found it caused more problems
> and didn't solve any.
>
> Point to Point routers
> Site 1: 10.2.0.2 -> 10.0.0.1 -> Site 2: 10.0.0.2 ->10.1.0.2
>
> Site #2 is set up like this.
>
> Internet NIC:
> 192.168.50.2
> 255.255.255.0
> 192.168.50.1
>
> Point to Point NIC
> 10.1.0.4
> 255.255.255.0
>
> I know I need to make an entry into the routing tables to make the
> point to point traffic use only the 10...etc NIC, but I'm not sure
> about the syntax. Any help would be appreciated.
>

I think that you are looking in the wrong place for a solution to this
problem. If you have two gateways on a LAN, the problem is how you decide
which one to use by default (ie what you set as the default gateway for the
workstations on the LAN).

Am I correct in assuming that there are two routers on the LAN -- the
Cisco which links the two sites together across a T1 and your server which
is acting as an Internet gateway for the LAN? If that is the case, your
server does not handle the site to site traffic at all. It simply redirects
it to the Cisco. All your server does is act as an Internet gateway.

If you want to use the Internet, the Internet router must be set as the
default gateway. The problem is that, if you do that, nothing goes over the
point to point link. The routing on the point to point routers may be
correct but no traffic ever gets to them. The Internet traffic goes out OK
but the private traffic is dropped (because private IPs can't cross the
Internet).

To get the traffic for the other site across the point to point link you
need extra routing on the LAN to get this traffic to the correct router. You
can add a route to every machine on the LAN so that it sends the private
traffic traffic to the correct router. A simpler solution is to add a route
to the Internet router to "bounce" the private traffic for your other site
to the correct router (ie you use the same static route but you only have to
put it on one device).

Internet
|
server/router {static route 10.2.0.0 255.255.0.0 10.1.0.2}
10.1.0.4 dg blank
|
workstations
10.1.0.x dg 10.1.0.4
|
10.1.0.2
Cisco
|
T1 to site 2

And a similar setup at the other site.

All non-local traffic on each LAN will go to your Internet
server/router. Internet traffic will continue on through the router. Private
traffic (for the other LAN) will be bounced to the Cisco which will send it
over the T1 to the other site.

Bill,

The servers at either end are not acting as gateways. We have another
router at each site that acts as our internet gateway, and the servers
are the only ones with access to the point to point. I had already
come to the conclusion that I need to add a static route on either end
to kick the 10. traffic to the Cisco routers instead of my internet
gateway, but am not sure how to format the "route add" command. Any
ideas, or could you possibly point me to a better place to get an
answer?

Thanks,
Clay

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
> Bill,
>
> The servers at either end are not acting as gateways. We have another
> router at each site that acts as our internet gateway, and the servers
> are the only ones with access to the point to point. I had already
> come to the conclusion that I need to add a static route on either end
> to kick the 10. traffic to the Cisco routers instead of my internet
> gateway, but am not sure how to format the "route add" command. Any
> ideas, or could you possibly point me to a better place to get an
> answer?
>
> Thanks,
> Clay
>

If these servers are the only machines on the LAN which can access the
point to point, then they are effectively the routers to the point to point
link as far as the LAN machines is concerned (if the LAN machines can't see
the Cisco). You can't route traffic to the other site via the Cisco directly
if it doesn't have an interface in the local LAN. You will need to route it
through the server which can see the Cisco. (A simple diagram of your LAN
layout would be a big help. What is the IP address of the gateway? What is
the network config of the workstations?) It is a pretty straight-forward
thing to do but I can't give you explicit details without knowing how your
LAN is configured.

The situation is essentially the same. The LAN machines send everything
to the Internet router by default. On the Internet router you need a static
route to bounce the private traffic to your server.

"Bill Grant" <not.available@online> wrote in message
news:eml6ulk%(E-Mail Removed)...
>
> <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed) oups.com...
>> Bill,
>>
>> The servers at either end are not acting as gateways. We have another
>> router at each site that acts as our internet gateway, and the servers
>> are the only ones with access to the point to point. I had already
>> come to the conclusion that I need to add a static route on either end
>> to kick the 10. traffic to the Cisco routers instead of my internet
>> gateway, but am not sure how to format the "route add" command. Any
>> ideas, or could you possibly point me to a better place to get an
>> answer?
>>
>> Thanks,
>> Clay
>>
>
> If these servers are the only machines on the LAN which can access the
> point to point, then they are effectively the routers to the point to
> point link as far as the LAN machines is concerned (if the LAN machines
> can't see the Cisco). You can't route traffic to the other site via the
> Cisco directly if it doesn't have an interface in the local LAN. You will
> need to route it through the server which can see the Cisco. (A simple
> diagram of your LAN layout would be a big help. What is the IP address of
> the gateway? What is the network config of the workstations?) It is a
> pretty straight-forward thing to do but I can't give you explicit details
> without knowing how your LAN is configured.
>
> The situation is essentially the same. The LAN machines send everything
> to the Internet router by default. On the Internet router you need a
> static route to bounce the private traffic to your server.
>
>
>
The more I look at this, the less sense it makes. Are you really using
192.168. IP addresses on the LAN? If so, why? If you have a point to point
set up to route between two 10. subnet, why would you use 192.168.
addresses?