Strange Ping behavior

[Flex727]

Perhaps not strictly a Unitronics thing, and likely there's something I don't understand about the PING function, but often when I try to Ping a Unitronics PLC (connected directly to it from my laptop) I'll get this strange response (see screen cap).

Notice the laptop IP address is 192.168.62.251 and the PLC IP address is 192.168.62.208. However it tries to Ping 192.168.50.208. What is it trying to do here?

[kratmel]

13 minutes ago, Flex727 said:

Unitronics PLC

Model # ? 

[Joe Tauser]

That's your computer identifying itself with it's own IP telling you that the PING did not get a response.

It confused me the first time I saw it.

 

Joe T.

[Flex727]

23 hours ago, kratmel said:

Model # ? 

It's a V700.

[Flex727]

19 hours ago, Joe Tauser said:

That's your computer identifying itself with it's own IP telling you that the PING did not get a response.

I get that, but what's with the 192.168.50.208? There's no .50 subnet in this network.

[Gabriel Franco]

maybe subnet used by another NIC

[kratmel]

As far as I understand, the result of this test can be reproduced many times.

My thoughts:

1) perform this test without connecting the PLC;

2) dial 192.168.62.208 instead of 192.168.062.208;

3) repeat the test by switching the PLC to STOP mode;

4) test another PLC (not V700) with the same settings.

[Flex727]

1 hour ago, kratmel said:

As far as I understand, the result of this test can be reproduced many times.

Yes it can.

1 hour ago, kratmel said:

My thoughts:

1) perform this test without connecting the PLC;

2) dial 192.168.62.208 instead of 192.168.062.208;

3) repeat the test by switching the PLC to STOP mode;

4) test another PLC (not V700) with the same settings.

Will do.

[Ausman]

I've seen my A/V play funny buggers with addresses at times, with the virtual adapters it uses.  Try with it fully disabled, just to check that isn't the cause.

And you haven't forgotten any leftover static specs in the adapter settings that might be upsetting things?

[AlexUT]

Do you have any VPN installed?

If yes-temporary disableit, or uninstall, than test again.

*I found that installed at my company's Laptop VPN created virtual network switches, allowed only company defined connections.

You may have similar problem.

 

[Flex727]

8 hours ago, AlexUT said:

Do you have any VPN installed?

No.

[Flex727]

On 9/1/2023 at 10:10 PM, Ausman said:

And you haven't forgotten any leftover static specs in the adapter settings that might be upsetting things?

No, I have to use static specs for this job as the customer has assigned .062 subnet to our systems.

[AlexUT]

192.168.

192.168.50.208 may be a default gateway.

1. Run from DOS prompt "ipconfig /all" and look in list for 192.168.50.208.

2. It may be a Proxy Server, set by company's configuration.

Enter "Proxy" in search box and press ENTER.

Check if any Proxy settings are enabled.

Probably you may see 192.168.50.208 as a Proxy.

Disable Proxy and check ping again.

3. In DOS prompt enter "tracert 192.168.50.208 and press ENTER.

*It works slow.

4. You can ping 192.168.50.208 if you are at company network.

It may answer you if exists and if ping reply enabled for this IP by IT.

Summary (not full list):

Proxy, Firewall, VPNs, AntiVirus/AntiSpam and other security applications, running by IT.

. Sometime helps if you reboot your computer.

[Flex727]

1. Done that - nothing found.

2. This is a personal laptop, no proxy servers.

3. I was connected directly to the PLC via crossover cable. No network, no wireless connection.

4. I should have tried to ping that address. Rats.

5. It's a laptop. It gets rebooted every time I use it.