Odd behavior while trying to set BRX IP address

[Controls Guy]

I have a bench BRX (BX-DM1E-36ED13) that I want to assign an IP address to, with no program, to send to a customer to make a communication test.

Attempt 1:  Hook up with NetEdit.   Finds device, shows 0.0.0.0 IP, says device type is unknown.   Attempt to write IP address and node number, tells me it can't write the node number.  Kill NetEdit.

2:  Try IPConfig.   Enter MAC and desired IP address and subnet, press Write, and it works.   Back to NetEdit, now shows current IP and recognizes CPU model.

3:  Go online, clear PLC memory (System unchecked), appears to clear OK.    Now cannot connect to PLC.

4:  Back to NetEdit, status back to original.  Finds MAC, no model recognized, IP 0.0.0.0.  NetEdit will not set IP with same error as before.

5:  Back to IPConfig.   Enter MAC, desired IP and subnet, select adapter, press Write.   Tells me it can't find the device, but some "old devices" may not accept a subnet mask, so do I want to write just the IP.  Sure, why not.  Still can't find device.

So.....

1) Why did Clear PLC Memory clear the IP address, when System was not checked?

2) Why will NetEdit not write to it at all?

3) Why can IPConfig not find it, and what changed vs. the previous iteration when it did?

[Controls Guy]

Next serving of weirdness.   Restarted DMD, tried NetEdit again (this time not trying to assign ID), and not only does it write the IP, it assigns the ID I wanted anyway.   

OK, NetEdit APPEARS to write the IP and it shows up in the list.

Go to DMD and it can't find the CPU.   Back to NetEdit and it's back to detecting the MAC, not knowing the model, and IP is 0.0.0.0

[BobO]

Never seen anything like this. Every time I've heard rumors of such things it has always been some combination of firewall/virus protection, multi-NIC weirdness, or VPN.

[Controls Guy]

I'm manually selecting the proper adapter in NetEdit, and in the connection dialog, I unchecked all adapters except the correct one.

I'll try disabling them all from Windows and see if it makes a difference.

Windows 7, no firewall, local hardwired connection.

I've never seen one fail before either.

[Controls Guy]

Never seen anything like this. Every time I've heard rumors of such things it has always been some combination of firewall/virus protection, multi-NIC weirdness, or VPN.

D'oh!   That has to be it.   I'm setting this to be the same IP as a customer H2-ECOM in a 260 so I can send them the BRX test some routing issues, so there's a route table entry for that whole subnet trying to send it to the VPN.  Let me turn the VPN off and/or delete the route table entry for the moment and see if normalcy returns.

[BobO]

...and duplicate IPs will do suuuper strange things.

[Controls Guy]

Nope, same.   Turned off VPN, and deleted route table entry.

NetEdit appears to set the IP,. and recognizes the model, DMD can't find it.  On return to NetEdit, back to showing the MAC address, but 0 IP and not recognizing the model.

Tried addresses in a new subnet, just in case some weirdness was still lurking having to do with the subnet I was trying to set up.  No change.

[Controls Guy]

...and duplicate IPs will do suuuper strange things.

Nah, it's a single cable straight from the PC to PLC, and I know both IPs.

Weird, it just started working.   Doo-doo-doo-doo   doo-doo-doo-doo

Only thing I did just before DMD got happy was that I pinged the PLC (successfully).  [shrug]

[Controls Guy]

Only thing I can figure is that it didn't work with the routing in place, as it shouldn't, but then failed for a while after the route was removed because there was some little thing somewhere that persisted for a bit.

[ADC Product Engineer]

Windows networking often requires a reboot even though it shouldn't. 

[franji1]

I wonder if you had configured the IP Address via Designer's Connect dialog you might have caught the duplicate IP Address.  Designer does an ARP table lookup and warns you if you try to configure a new IP Address to something that is in the ARP table already.

However, it would still have let you assigned it after that warning (e.g. when swapping IP Addresses), and you would have had the same issues, but at least it would have raised a red flag and hopefully you would have caught it and resolved it.

NetEdit is generic for HEI devices (ECOMs, EBCs, GSEDRVs, MBIO, ...).  The new Connect dialog in Designer has a lot more capabilities for setting up a connection to a Do-more PLC, like duplicate IP Address checks (consistent subnet checks, ...).  We should add that functionality to NetEdit.

[brucek]

Glad its working now but just a question? Did you try to use the usb and change it thru the info tab? Something rings a bell that I had to do that once but might have been because we forgot the ip address so didn't know what to set the laptop to in order to connect. I've been able to change the ip address to what I want thru there and then get to it by the ethernet.

[Controls Guy]

Windows networking often requires a reboot even though it shouldn't.

Yeah, I didn't reboot before it started working, but it had to be something like that.

[Controls Guy]

Glad its working now but just a question? Did you try to use the usb and change it thru the info tab? Something rings a bell that I had to do that once but might have been because we forgot the ip address so didn't know what to set the laptop to in order to connect. I've been able to change the ip address to what I want thru there and then get to it by the ethernet.

No.    I'm having trouble reaching a 260 via VPN at a customer site that I can't get to at the moment, so I was setting up an Ethernet BRX with the same IP and gateway to send to the customer to plug in in lieu of the 260 when they're not running.   Then I can check the routed access to the BRX.    The problem, which BobO tipped me off to, was that since this IP address is normally one that I reach via VPN and routing, there is a route table entry telling Windows to use the VPN adapter to talk to anything in that subnet.   So if NetEdit successfully sets the IP, at the same time it's breaking the connection to the physical LAN adapter connected to the PLC via cable.   Once BobO mentioned VPNs, I flashed on what the issue was and deleted the route table entry.   One of those D'oh moments.

[Controls Guy]

Glad its working now but just a question? Did you try to use the usb and change it thru the info tab? Something rings a bell that I had to do that once but might have been because we forgot the ip address so didn't know what to set the laptop to in order to connect. I've been able to change the ip address to what I want thru there and then get to it by the ethernet.

If you've set and forgotten an IP address, I believe the IPConfig utility in Launchpad can still set the IP via the MAC address (printed on the POM PCB or the serial number for Ethernet Do-Mores)
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Another trick that sometimes works with a port that has a fixed but unknown IP is to hook up to it, start Wireshark, and the port is often ARPing around announcing its IP address.