Why these 2 PC's can't ping each other? Please Help!!

[qball419]

This driving me crazy. Ok…here’s the deal. I have a Dell with Windows 2003 Server and it has 2 NIC’s—but the one that I am concern with has an IP of 192.168.2.1. This is connected to a Linksys 4-port switch. I have also have an IBM (also with Server 2003) that is also connected to that switch. The IBM’s NIC has an IP of 192.168.2.100. Both of these IP addresses are statically configured. The cables, switch, and NICs are working fine...double-checked on them. Both machine indicated that its NIC are indeed “Connected”. But for some reason, they are not able to communicate with one another. I can’t ping either machine from either computer. I have no idea what is going on. There is no firewall on either machine. Both have the same subnet mask. They are on the same subnet…yet can’t ping. Why?

Here are some more info: The default gateway of my Dell's NIC is blank. It is left black because my Dell has another interface, which is 192.168.1.100. This interface's default gateway points to my NAT server (for Internet access) which is 192.168.1.1. On my IBM, the default gateway of my NIC (192.168.2.100) is 192.168.2.1.

So, the setup looks like this: NAT(1.1)---Dell NIC1(1.100)||Dell NIC2(2.1)---switch-----IBM NIC(2.100).

Seems to me like when you have two machines that are on the same network as indicated by their IP and subnet mask. You hook them via a simple switch, then you should be able to ping and communicate, but this is not happening. I have no idea at this point why that is. Maybe I am missing something here.

Can somehow please tell me how to troubleshoot this? Any advice here would be great. I just can’t think of anything at this point.

Q

[Fix-your-comp]

Are they on the same workgroup?

[benzimm86]

first of all see if you can ping your own ip address. for the server with two ip address's ping them both. if you cant do that, you have an idea where to start.

even though one of your nics has a default gateway setup i believe the other must as well even if it is just your other nic. if the ping is going out through the nic with no gateway that might explain how it is getting lost.

[qball419]

Hey...thanks for the response. First of all, these PCs are on the same Windows domain. Second, I have change the gateway of the Dell's NIC to 192.168.2.100 and still not able to ping. And yes, I can ping my own IP on both machine. And I can ping both NICs on my DELL.

These machines are on the same subnet. They are connected via a simple switch, yet they can't communicate. This is baffling. I mean, even if I leave the default gateway blank on either NIC, they should be able to talk to each other, right?? Anyways, anyone with any idea, I would love to hear you out. Thanks.

[Law]

Maybe they hate each other....

[Law]

Anyways just to help you out a little, I know how frustrating it can be and this situation of yours is frustrating to me also =). I was just thinking if ping doesn't work that would mean there's something going on at the lower layer. Now start checking layer 2, (the switch and network card). Suggestion, if it's a manageable switch you can try to ping it (only if it's configured with an IP address). Do a loopback test for all the NIC (127.0.0.1). If all is good move down to layer 1 (the cables). Make sure they are straight through cables that are connecting to the switch. Check for bending or damage, it might be faulty, make sure it's securely connected, make sure the lights are on. That's pretty much all I can think of as of now.

[qball419]

Just want to inform the forum that this issue has been resolved. It was my NIC that was acting up. I uninstalled the network card and reboot the system and it works!! Thanks to all for trying to help me.

Law: You were right on with your initial assessment. It was indeed a problem with the lower layer (switch or NIC). I had initially rule out the NIC simply because I was able to ping the IP itself...but didn't think I ping the local host (127.0.0.1)...I figure they are one and the same. What I did was use a laptop, configure a static IP of 192.168.2.X and connect it to the switch. From there I wasn't able to ping Dell, but got a reply from the IBM. I immediately ruled out the IBM and focus on the Dell. Suffice to say, I am one happy camper. Thanks for your help.

[Ethereal_Dragon]

When pinging the address 127.0.0.1 from a PC, it doesn't validate all of the layers. This is the loopback address, and it validates layers 3-7 on that PC...