Win 7 laptop on a static IP won't communicate/ping via its wired Ethernet port

A production dept desktop and validation dept's laptop both communicate (using the HMI app) to the HMI through a couple local CAT cables and unmanaged switch on a private network using static IPs with no gateway settings, proving the HMI and associated hardware outside the new laptop works OK.

The new Win 7 Pro laptop will not ping/communicate to the HMI via the laptop's wired Ethernet port with the laptop on a static IP.

To check the Ethernet port, I
- disabled the WiFi wireless adapter (so the only way to communicate is through the wired port)
- set the wired adapter to DHCP
- connected a CAT cable to the corporate network and found that Internet Explorer connected to the internet just fine using the wired port.

But when the port is re-configured with a 192.168.X.XXX static IP address (subnet mask 255.255.255.0), and the laptop substituted for the production desktop that communciates with the HMI, the laptop will not communicate with the HMI using the HMI app program. An attempt to ping the HMI times out.

I checked the Windows Firewall and the HMI app program is enabled for both private and public networks.

In my experience, failure to ping a point-to-point connection (through a working unmanaged switch) has either been a hardware issue
- CAT cable not plugged in
- switch power disabled/disconnected
- bad connector on a CAT cable

or an IP address issue
- a wrong subnet IP address
- DHCP is enabled rather than a static IP

I'm guessing the Windows firewall could stop a ping or a app program, but what would I look for?

Any other ideas?

Dan

The first 3 of 4 numbers must match.
With Weintek HMI software EB Pro, I can't download if HMI is 192.168.0.xxx, and my PC is 192.168.1.xxx.
Both must be 192.168.1.xxx or 192.168.0.xxx, etc.

Edit. I think this started when I upgraded from XP to Win7. Was still true with Win10 Home and Pro.

My mistake for not being exact.

All subnets IPs for these devices are 192.168.7.xxx.

Changing Laptop's Protocol 4, IPv4, not IPv6?

You have a setting wrong somewhere. What are the full IP addresses you are using to configure the networks?

The second option is to try swapping the ports/wires in an organized fashion as well. I have seen intermittent issues with mis-crimped pins on cat5 cables as well. They could send data but not receive data.

I'm thinking your troubleshooting is correct, but you need to go through paying more attention to tiny details as you probably missed something in your initial pass.

>Changing Laptop's Protocol 4, IPv4, not IPv6?
The HMI is IPv4 only, so I actually disabled IPv6 on the laptop.

>What are the full IP addresses?
HMI = 192.168.7.36
laptop = 192.168.7.100

The Ethernet switch is a 5 port with 5 commercially constructed 7' cables attached. I have tried 4 of the 5 cables, testing each with my laptop to prove functionality before trying the bad-boy laptop. I have tried the bad-boy laptop with each of those four cables.

I reset the power to the switch each time I tried different cables/ports because I've learned that swapping ports sometimes confuses cheap switches.

I've also tried direct connection (laptop to HMI) with a straight-through CAT cable (no switch), which worked OK with my laptop, but not with the bad-boy laptop.

What is the response? Timeout or destination unreachable?

Disable Windows firewall.

Run wireshark or angryIP scanner on the laptop to have a look at what it can see (if anything).

Run those tools on one of the other PCs (while the laptop is connected) to see if the other machine can "see" the laptop...

This link below has a humourous title, but it did work for me when my network adapter was in "no man's land"

https://www.hanselman.com/blog/TheNuclearOptionResettingTheCrapOutOfYourNetworkAdaptersInVista.aspx

Use the same cables and the same port on switches. Disconnect old pc and replace it with the new and the result is?

Is Windows showing Unidentified Network, or is it Work or Home?

>What is the response? Timeout or destination unreachable?

Ans: Before I disabled the Wi-Fi wireless port, out of the four ping attempts it would report a couple time-outs and one or two destination unreachable at an IP in 10.x.x.x subnet, an IP address I was not pinging.

I figured ping was confusing wired and wireless ports, so I disabled the wireless port and subsequently got all four "timed-outs" for a ping.

>Disconnect old pc and replace it with the new and the result is?

Ans: HMI app reports that it cannot connect, ping says "timed out". 100% loss

>Is Windows showing Unidentified Network, or is it Work or Home?

Ans: Unidentified Network

>Disable Windows firewall.

Thanks for advice. I'll have to wait until Monday to try it - it's a production Dept PC that can't leave the premises.

sigmadelta said:

This link below has a humourous title, but it did work for me when my network adapter was in "no man's land" Link

Click to expand...

The title scares me: nuclear option. I saw the grocery store shelves and hunting supply store shelves empty during the Cuban Missile crisis.

Are these commands erasing current drivers/whatever that are supposed to re-install on the next boot, or am I supposed to find and manually replace something for each nuclear action?

The suggestion for prayer makes me wonder whether the prayer is that the combined actions fix it or whether one is praying that it isn't worse afterwards than what one starts with.

danw said:

>Is Windows showing Unidentified Network, or is it Work or Home?

Ans: Unidentified Network

Click to expand...

Your IT department may have a group or local policy setting to not allow or heavily restrict comms when Windows sets it to an unidentified network. Try and change the network location to Home or Work in Network and Sharing Center. If that fails, be sure that there is a default gateway IP address set to a switch that actually exists on your network. Windows generally won't set a Work network without a gateway address. If that can't be done, or has no effect, goto Control Panel > Administrative Tools > Local Security Policy > Network List Manager > Set the location type to Private for Unidentified networks.

Are these commands erasing current drivers/whatever that are supposed to re-install on the next boot, or am I supposed to find and manually replace something for each nuclear action?

Click to expand...

No device drivers are affected. I ran the commands one after the other in a command prompt, and rebooted at the end. The only thing to do beforehand is to take note whether or not each of your network adapter IPv4 settings have Static IP(s), Subnet Mask(s), and Gateway(s) set, because you will have to re-enter that information. If your network adapters are set for DHCP, you automatically receive IP/Subnet Mask/Gateway from your DHCP server, and there is nothing you need to take note of.

The suggestion for prayer makes me wonder whether the prayer is that the combined actions fix it or whether one is praying that it isn't worse afterwards than what one starts with.

Click to expand...

This is a joke. Sometimes the problem could be just the Ethernet cable, router, broken Ethernet port, etc. So it may fix it, or something else is still the problem.