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SBS 2003 DNS Forward Lookup Zone to a differnet subnet

Need SBS 2003 Server to connect to another subnet
- I have a SBS 2003 Server configured on a local lan ip range of 10.121.50.xxx using .10
So the DNS, DHCP and Gateway is for the XP PRO workstations on the LAN.
- All the workstations and server LAN connection are connected to a 24 port switch.
- The Server has a second NIC configured to a broadband modem to the ISP.
- Special configuration, there is a T1 cisco router also connected to our switch with a gateway address of and all the workstations have their gateway set to this one instead of the default one. The cisco router is now set to re-route internet and email traffic back to the SBS 2003 gateway at and allow everything else through (they use AS400 applications using emulation programs)
- My question is how do I get the SBS server to get to or recognize all the other IP adresses that the workstations can see. The server can only ping the gateway at this point. I thought maybe setting a bridge up on an additional NIC but I've read in previous posts the SBS does not allow Bridges.
The reason for wanting this is to create a forward lookup zone to a DNS server on the other side of that gateway. The easiest solution would be prefered.
Thank you in advance.

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8/22/2022 - Mon
Imtiaz Hasham

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I don't want to add a second Windows 2003 server. We have a SBS (Small Busines Server) 2003 and this is already acting as a gateway to our ISP using its own IP of The problem we have is the workstations need access to the gateway for AS400 applications located on servers behind this gateway and when standing at the server I can ping the gateway at but can't get ping replies from any of the server IP's

Everything works fine except I am trying to setup a forward lookup zone from server 2003 to their DNS server which is located on the other side of the gateway.

I'm not sure but I hope its more clear now. Maybe I should have posted in network zone as well but I thought I would start here because of it being a Windows 2003 Server and the specialty of this platform. Our server is the premium addition so it includes the ISA Firewall.

Any ideas would be much appreciated and I would like to select a solution that does not adversly effect the Small Business Server's abilities such as Exchange E-mail and the POP3 connector.


More information : Our SBS Server 2003 gateway at is going out to our ISP using DSL and the Cisco Router is for the gateway at and gets us to these other servers using a corporate privagte T1 line.

More information: I know I can't setup a second gateway on the SBS Server 2003 is there a way to get this server to talk this other subnet. Maybe a bridge? Or is there another way to do this using one of the other functions in the SBS 2003 Server?
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Walt Forbes

Wow, this is complicated!

I have 2 thoughts to bounce around, not sure if either will work.   1)   Is it possible that you need to allow the emulator software's port through your sofware firewall on the SBS?   You are able to ping, which is proably allowed, but I am guessing you are not connecting.   2)   What if you added a 2nd IP to your NIC card, in the 10.121.1.x subnet.   You server would automatically start routing traffice for this subnet through that interface and IP.

I think this can be resolved internally.  I don't think anything relating to the ISP should matter.

Good Luck!,   Chris

camori : Sorry for the delay in responding,

I'll try to explain it slightly different and hope it makes it easier to understand.

The problem I have is here is that we have 2 gateways
  - The Small Business Server is setup as one gateway at
  - The Cisco Router also has a gateway at
  - All the XP PRO workstations have an IP on 10.121.50.xxx subnet
  - All the XP PRO workstations their gateway set to
    (this allows the workstations through the Cisco Router gateway to access a large corporate network)
   ( Because of the class of the TCP/IP or the way the Router is configured or both, the workstations are able to access servers at 10.1.2.xxx,  10.1.3.xxx,   10.1.4.xxx ect .. )
  - They also have a DNS server at ( this is where I would like my DNS server at the Small Business Server to forward unresolved names.)
  - The workstations can ping all these servers because their gateway is set to
  - My Small Business Server cannot ping all these servers because it does not have a gateway set for
    - If I add another IP on the same LAN NIC at the 10.121.1.x will I be able to set another gateway to for the Small Business Server to start pinging the corporate network?
  - If so what is the procedure for adding another IP and gateway?