Definitely OT: network settings

[J. Dan]

I've had some Facebook discussion so I'll try to summarize what's already been discussed and the challenges.

 

More and more with industrial products (think some device that measures temperature, pressure, flow) they have an Ethernet port with a built in web browser for interface. Each device has an IP address, you use your browser, type the IP address, and get a page to monitor readings and change configurations, I have all that working just fine - set my local network card to a fixed IP, type in the IP of the device, great.

 

Here's the problem - I need to demo this live via webex. Normally as soon as I plug in a cable, instead of wifi, my computer tries to use the local connection, which is not connected to the Internet. It's a peer to peer connection to the device. I made some changes to my wireless card settings and successfully streamed a YouTube video while interfacing with the local device in another browser window. However webex didn't work. As soon as I plugged in the cable I got dropped from the meeting and it was trying to reconnect through the local connection,

 

Any ideas?

[JB Sherry]

I use Webex over Ethernet all the time. The issue is the network. You need to customize the network settings of the device do that it's in the same subnet as the Internet gateway router. I suspect you've been changing your computer to match the device but you'll have to do it the other way around. Check your computer network settings to determine the gateway IP address and set your device so it has an address in the same network.

 

If you can't change the device address, or if you'll be demoing this on various customer sites, get yourself a wireless router to carry around. Set the private network of the router to match the device network, and plug your computer into the private network and the router will get you onto the network that has the Internet gateway.

 

Addendum: doesn't actually need to be a wireless router, just a router, if anyone makes cheap consumer routers without wireless anymore.

Addendum 2: my initial suggestion presupposes you can plug both your computer and your device into your network rather than connecting computer to device via Ethernet. You can do this at home if you set up in proximity to your wireless router, which probably has 4 or 5 Ethernet ports.

[Mighty Ferguson]

You should be able to do this without having to move the IP address of the device onto the same subnet as the wifi. That way may or may not be simpler depending on the impact of changing the device. It sounds like you were on the right track before if you were able to connect to the device via Ethernet and YouTube via wifi. It's a question of routing. For this configuration you want the wifi to get IP/mask, default route, and DNS servers for your main Internet connected LAN, probably via DHCP. Then you'll assign a static IP/mask for the Ethernet port in the same subnet as the device, but it should have no default route or DNS. The computer will not need any routing for the device as it will know it's directly connected to the same subnet. All internet traffic should follow the default route out the wifi. This method does work, I do it all the time to configure network equipment.

[J. Dan]

Thanks for the pointers, I'll so some experimenting later today, one suggestion was to connect the drive to the router rather than try to use multiple connections directly from my laptop.

[Ulf]

I do this all the time and have found a separate USB-to-Ethernet to be the best and most reliable solution.

 

Keep your main configuration (wired and WiFi) as you or your employer admin wants it, and adjust the USB dongle netmask/adress as needed for you peer device.

[WesG]

Webex is a screen sharing + conference calling program, right? I think I used it once a zillion years ago.

 

The issue you're going to bump into is network routing if the device isn't using the same network address as the rest of your network (and I'm assuming this is the case, since you have to change your IP number).

 

The EASIEST way to work around this issue is to plug the device into one network interface and use your local network on another. Sounds like you are doing this, with the hardware device hanging off your wired port and your local network on the wireless.

 

I suspect the issue that's happening is that the PC is using an incorrect default route when wired NIC becomes active. Possibly because of settings in your network interface (control panel), possibly because the device might be sending it with DHCP (sounds like this isn't the case since you're changing addresses).

 

So...changing the routing table in windows.....there is a "route" command from cmd prompt if memory serves me correctly. I'm not a windows guy, so I'll give you approximate Unix commands and you can go from there --

 

# route print

(locate the incorrect route A.B.C.D -- it will send 0.0.0.0/0 to the ethernet port address instead of the wireless nic)

# route delete default A.B.C.D

(the address of your Wifi router is W.X.Y.Z)

# route add default W.X.Y.Z

 

Also, "default" is usually a synonym for 0.0.0.0

 

Follow up if you bump into trouble......this is my area of expertise but I haven't really used Windows in over a decade.

 

Wes

 

Wes

[WesG]

Another possible solution. It's stupid from a network engineering point of view, but it will work.

 

Plug your hardware into one of the router's LAN ports. Then add a *second* IP address to your wireless card. There should be an option under the advanced tab to add more addresses (maybe called aliases). The *second* IP address needs to be the one you were previously assigning to your hardwired port.

 

This will probably trick everything into working properly, even if it's stupid from a lah-dee-dah networking engineering design POV. And if it works it will be reliable, provided you don't plug in conflicting devices.

 

If it doesn't work at all, it's probably because of Layer 3 filtering on the router's part. I don't think that's common, I expect most routers to bridge between the wireless and LAN ports at Layer 2.

 

Wes

[MoodyBluesKeys]

WesG recommendation. Second IP address (except that IF you plug into a router LAN port, you connect using the Ethernet connection, not the wireless connection).

 

Alternative for notebook: Two Ethernet connections, one as above plugged into the router, second using a USB to Ethernet device. Routing tables have a tendency to get out of sorts with both Ethernet and wireless devices, especially if IPv6 is left turned on. If it is possible to avoid using the wireless connection it is better (because of the encryption/security on the wireless).

 

Even just turning off IPv6 and only running IPv4 might well help your situation (the whys on this get into fairly deep theory, but IPv6 adds a lot of behind the scenes stuff and increases the complexity of the routing table). It is also possible to manually add and/or delete routes in a routing table using command prompt syntax, but that gets complex so if it can be persuaded to work with the automatic route table, that is best. BTW, the command syntax is the same under Windows.

 

Might just do a "route print" command to see if there are two different lines that route 0.0.0.0 (which means anything that is not specified in the table - in other words a gateway)

 

I've had to do similar things frequently, especially if setting up a managed Cisco switch or router, which will start off on the default IP and has to be changed to match the network.

 

If all else fails and you have available two computers, you could probably have the industrial device displayed on one, the webex connection on the other, and use Windows Remote Desktop to see and control the device computer.

[Hoochie]

Is this a device in place and you are roving to it while it's in production?

And training staff on using it?

It might be separated off in its own VLAN or layer 3 space.

You can get advanced drivers for your NIC (Ethernet adapter. You plug in your computer to the network here)

Those advanced drivers allow you to set the VLAN on your computer.

You may have to manually set your IP too if it's that locked down.

But unless that VLAN has routing to get out this could break it too.

Because your connection is basically moved off into virtual space.

Don't forget to undo this. I always forget.

 

 

If you have a demo device that roves with you perhaps this?

 

Get a small Wireless Router

Plug your things you move with you into the Lan ports of that router

(They will get their address and stuff from your wireless router.

The laptop will get its stuff from that wireless router too.

You'll of course have to get your laptop on that WAP) (Wireless Access Pount)

 

Plug the wan port of the router into the customers network.

Make sure the wan port is set to DHCP and it will get an IP address

off the customers network and your off to the races.

(Most of these basic wireless routers are preconfigured to send all traffic

routed to the WAN ports address. That address will be like any computer just plugged in. Which in most cases your good.)

 

There of course are instances where this may not work.

There could be no DHCP or they could have a firewall

that's too intrusive, mac filters, VLANs, POLICIES,

aaaaaaauuuugghhhhh!!!!

But your essentially making your own network

within a network.

A small scale version of what you do at home when you

plug in to your DSL router.

The carriers have a backbone router handing out

addresses to the DSL's etc.

 

I could write a book about this but if you want to pm

me you can. This is the kind of thing I deal with

on a larger scale all day long.

Keep it simple. You'll keep your hair longer.

Try it at home first to make sure your good.

 

 

John

 

[J. Dan]

Hey all, thanks for all the great suggestions. The extremely simple solution was just to plug the device into my router instead of directly to my laptop....worked like a charm.

[MoodyBluesKeys]

Well done, Dan. People with a lot more networking experience have fought routing problems a lot longer than that.

 

Kinda does make sense to let the router do the routing - it is designed with the idea that there will be more than one device accessing it at once.

[J. Dan]

Yeah, kind of a "duh" moment