2 NIC cards IP Conflict

[tstand]

Hi Everyone,
2 NIC cards are installed on PC (win7) –one for corporate network (DHCP -10.10.x.x) and second one for UUTs (Static 192.168.1.110-113, with smart switch GS108T).
SQL server (store test reports) is at IP 10.10.x.x and unfortunately one of the CORP network device uses 192.168.1.113 which is same address as one of the UUTs.
Is there a way to disable on corporate NIC card the IP range 192.168.1.x so as to eliminate IP conflict between UUT and the network device?

Thanks,

tsstand

[Captain_K]

Hi Tstand,

I’m by no means a networking expert but I’ve attached a couple links that might be of help for disabling IP ranges.

http://superuser.com/questions/335817/how-can-i-disable-network-connectivity-to-a-particular-port-or...

https://www.cm3solutions.com/block-ip-address-ip-range-using-windows-firewall/

Do you have an IT team available to you?

[tstand]

Thanks Matt,

I just wonder if there is a collection of best practices from TS comunity, as this is a common issue most test engineers will encounter in the production environment.

I would like some input or suggestions from TestStand's experts and gurus as to how they approach this type of scenarios (either avoid or resolve)?

Thanks again,

tstand

[tstand]

Any ideas, additional input or sugesstions?

~jiggawax~

dug9000

RayFarmer

Dennis_Knutson

[mkossmann]

If the NIC/Network  configuration on the Test-PC is right, it shouldn't try to send any packet to the 192.168.1 Network over the NIC for the 10.10  network.

Could you show us the output of ipconfig /all  and route /PRINT ?

[tstand]

Hi mkossmann,

Thanks for your response and to expand some more about this issue:

Corporate connection is DHCP and UUTs are static IPs (via smart switch) 192.168.1.111-114.

There is a ping function (teststand code) that ends very quickly (IP 192.168.1.113) even though UUT not even finish boot-up process; which tells me we are getting response from network device with same IP address (via corporate NIC card).

Then, my question:  Are there any other solutions to this common issue most test engineers will encounter in the production environment, other than Matt has indicated previously.

Or, other best practices when using two NIC cards approach, such using a combination of routers, switches, HUBs, smart SW, etc, to avoid this kinf of IP conflicts?

Thanks again,

 tstand

[mkossmann · Accepted solution]

Normal rules for sending IP packets are:

First check if the packet goes into a "local network".

A "local network" is defined by the IP address and network mask of the Interface(NIC) 

If the packet goes to a "local net"  the packet is sent through the matching interface ( and no other interface) directly to the target.

If the packet doesn't go into a "local network" it is sent to the "default gateway", which should know , how to send it further.

You can define exceptions to that normal rules by setting up a route.

If your diagnosis ( conflicting IP address in corporate network) is right, there has to be a special route setup in  your PC . That is , why I have asked you for the output of route.

Other sources of the conflicting IP address I can think of:

You may use the .113 address for a NIC in your PC

(Remember that you can define more than one IP address for one Interface/NIC).

That should be shown by the output of ipconfig /all

A "smart switch" may have a configuration interface , which uses that address.

For further diagnosis Windows provides also a tracert command , which lists the hosts, a packet passes.

To see if the IP address is used in a "local network", look at the output of arp -a (after the first response to ping) .

The IP address and its correspondending MAC address should be listed there.

A MAC address should be unique . So you can use the tool at https://macvendors.com/ to identify its manufacturer

[mkossmann]

One addtion:

Did you check if  the network masks are right, to ensure that your UUTs are in one "local network"

[tstand]

Hi mkossmann,

Fortunately our IT group remove this device from our network and issue resolved.

I really appreciate your input.  Thanks very much,

tstand