Using 2 Network Cards - Directing Different Traffic Over Each

jamesd

I have a pc that talks to 2 networks:

Nic 1: 10.105.125.119 , 255.255.255.0 gateway 10.105.125.11
Nic 2: 192.168.7.1 , 255.255.255.0

(Pc can ping both networks with no issues)

There is software running on this pc that talks to devices via nic 2 but
this software then needs to send some detail out to an ip on the other network to 10.105.125.9

(the pc waiting 10.105.125.9 is listening for it on port 5007)

Can I use a static route for this? Does both devices having the same subnet matter?


I think I need to force any traffic out for 10.105.125.9 out via Nic 1 (10.105.125.119)

jamesd

Here is an ipconfig /all
C:\>ipconfig /all

Windows IP Configuration
Host Name . . . . . . . . . . . . : tronix
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Hotel Network:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Realtek RTL8168/8111 PCI-E Gigabit E
thernet NIC
Physical Address. . . . . . . . . : 00-1C-C0-02-1F-F7
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 10.105.125.119
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 10.105.125.11
DNS Servers . . . . . . . . . . . : 159.134.237.6

Ethernet adapter BMS Network Purple Cable:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : TP-LINK Gigabit PCI Network Adap
ter
Physical Address. . . . . . . . . : F8-1A-67-03-F2-B6
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 192.168.7.1
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . :

jamesd

Here is a print route:

C:\>route print
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...00 1c c0 02 1f f7 ...... Realtek RTL8168/8111 PCI-E Gigabit Ethernet NIC
- Packet Scheduler Miniport
0x3 ...f8 1a 67 03 f2 b6 ...... TP-LINK Gigabit PCI Network Adapter - Packet
Scheduler Miniport
===========================================================================
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 10.105.125.11 10.105.125.119 30
10.105.125.0 255.255.255.0 10.105.125.119 10.105.125.119 30
10.105.125.119 255.255.255.255 127.0.0.1 127.0.0.1 30
10.255.255.255 255.255.255.255 10.105.125.119 10.105.125.119 30
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
192.168.7.0 255.255.255.0 192.168.7.1 192.168.7.1 20
192.168.7.1 255.255.255.255 127.0.0.1 127.0.0.1 20
192.168.7.255 255.255.255.255 192.168.7.1 192.168.7.1 20
224.0.0.0 240.0.0.0 10.103.128.119 10.103.128.119 30
224.0.0.0 240.0.0.0 192.168.7.1 192.168.7.1 20
255.255.255.255 255.255.255.255 10.103.128.119 10.103.128.119 1
255.255.255.255 255.255.255.255 192.168.7.1 192.168.7.1 1
Default Gateway: 10.103.128.11
===========================================================================
Persistent Routes:
None

Cuddlesworth

It should just work. Since you have a IP in both subnets, hence why you can ping both. The logical path for traffic is to a local subnet, or through the gateway(routing). Only issue I could see is if the app was specifically setup or programmed to only use a specific NIC. Which would be unusual.

Alun

AFAIK Windows doesn't by default route between two different NICs on the same machine. If you type ipconfig /all, you can see at the very top of the output the line " IP Routing Enabled. . . . . . . . : No". There's a registry setting you can change to enable this ...

Set HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\IPEnableRouter to 1 (it's set to 0 by default). (EDIT: and reboot afterwards!)

You'll also need to make sure you have a default gateway on the device connected to NIC 2 (the IP on NIC 2 of your PC) if you want it to communicate with another device on the network connected to NIC 1.

jamesd

Cuddlesworth wrote: »

It should just work. Since you have a IP in both subnets, hence why you can ping both. The logical path for traffic is to a local subnet, or through the gateway(routing). Only issue I could see is if the app was specifically setup or programmed to only use a specific NIC. Which would be unusual.

No the app on the pc I am told should just be looking for 10.105.125.9 but it does not seem to work.

I did a little test:
On the network where all the devices are (192.167.7.x range) there is a switch where they all come back too ,I plugged in a cable to this switch from the 10.105.125.x network and all then worked. (When I plug out the cable it stops working)

Now I dont want to leave it this way as this pc was supposed to be the only link for network security reasons.

jamesd

Alun wrote: »

AFAIK Windows doesn't by default route between two different NICs on the same machine. If you type ipconfig /all, you can see at the very top of the output the line " IP Routing Enabled. . . . . . . . : No". There's a registry setting you can change to enable this ...

Set HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\IPEnableRouter to 1 (it's set to 0 by default). (EDIT: and reboot afterwards!)

You'll also need to make sure you have a default gateway on the device connected to NIC 2 (the IP on NIC 2 of your PC) if you want it to communicate with another device on the network connected to NIC 1.

Yes I see that "" IP Routing Enabled. . . . . . . . : No" when I do that, If I make that change then they should route between each other is it? I really only want NIC 2 to be able to communicate with NIC 1 only for communication to 10.105.125.9.

I dont want the devices connected to NIC 2 to communicate with NIC 1's network but I do want NIC 2 to be able to communicate with NIC 1 only for communication to 10.105.125.9

Alun

I've just re-read your original post, I was initially under the impression that you wanted the devices on the networks connected to each NIC to communicate with each other, but upon re-reading it I see it's only the PC that needs to communicate with the machine at 10.105.125.9.

So as Cuddleworth says, it should just work. First thing is to check connectivity ... can you ping 10.105.125.9 from the PC, and vice versa?

jamesd

Thanks - I am back at this site Monday again.

From the pc I can ping the destination server no bother 10.105.125.9 and from it ping the 10.105.125.119 pc.

Is the allow routing needed or is that to only allowed the 192.168.7.x network to get through?

Alun

No, after re-reading your OP, I'd say you don't need routing enabled at all. If I understand correctly the PC needs to be able to talk to whatever devices are on the 192.168.7.x network, gather data from them, perform some processing on that data and then send it to the machine on 10.105.125.9. All of this should be possible with the current setup without enabling routing on the PC at all. I can't see why anything on NIC 2 needs to directly access the network on NIC 1 at all, unless there's something else I'm not understanding about the setup.

So, at an operating system level, the PC can access both networks without problem, but the only fly in the ointment could be the application itself, which could maybe be written in such a way that it won't work properly in a dual NIC setup. Is this a configuration that the manufacturer of the application explicitly supports, do you know? Might be worth asking them if you haven't.

jamesd

Alun wrote: »

No, after re-reading your OP, I'd say you don't need routing enabled at all. If I understand correctly the PC needs to be able to talk to whatever devices are on the 192.168.7.x network, gather data from them, perform some processing on that data and then send it to the machine on 10.105.125.9. All of this should be possible with the current setup without enabling routing on the PC at all. I can't see why anything on NIC 2 needs to directly access the network on NIC 1 at all, unless there's something else I'm not understanding about the setup.

So, at an operating system level, the PC can access both networks without problem, but the only fly in the ointment could be the application itself, which could maybe be written in such a way that it won't work properly in a dual NIC setup. Is this a configuration that the manufacturer of the application explicitly supports, do you know? Might be worth asking them if you haven't.

Yes I think you could be right and it must be the application, the manufacturer has said it should work but I think it must be an issue on their side thats stopping it talking to my server.

I will update here next week.

Cuddlesworth

jamesd wrote: »

I did a little test:
On the network where all the devices are (192.167.7.x range) there is a switch where they all come back too ,I plugged in a cable to this switch from the 10.105.125.x network and all then worked. (When I plug out the cable it stops working)

That would imply one of two things.

A firewall is blocking communication out of the second NIC or the app itself is specifically looking to talk only through the 1 adapter, which as I said before is unusual.

jamesd

Tested today and from the pc I can ping both networks and from my server I am able to ping the card in the pc with no issues.(Card on same ip range).

Going back to software guys now.

jamesd

Ok major mess up for the 3rd party's side, the pc is not what talks to the business's server at all, they have a gateway device on their own network that talks to our server.
That is why it was not working.

Thanks for help guys.