Slashdot Mirror
Ask Slashdot: Best Way To Solve a Unique Networking Issue?
New submitter petro-tech writes: I work as a service technician, maintaining and repairing gas pumps and POS equipment. In my day to day activities, one that consumes a ton of time and is relatively regular is the process of upgrading the software on pumps. This is done by connecting to the pump via direct ethernet from my laptop, then running a manufacturer-provided program that connects to the device and pushes the new software. Some sites have 8+ pumps with 2 devices in each, and at 20-30 minutes apiece this can be quite time consuming. Unfortunately the devices are not actually on a network, and as such cannot be updated remotely, also since they are not on a network, they are all configured with the same IP address. Additionally the software doesn't allow you to specify the adapter to use. I would like to be able to get to a site, connect a cable to each pump, and load them all at the same time. The only way I can figure to accomplish this with the software we've been provided is to do this: Get a 16-port powered USB hub, with a usb-ethernet adaptor in each port; Set up 16 VM's with extremely stripped down XP running on each, with only one USB-ethernet adaptor assigned to each VM; Set XP to boot the application for loading software as its shell; and load each device that way at the same time. Is there a better way to accomplish this?
Have a question for Slashdot's readers? Take a look at other recent questions first to see if someone else has had a similar question. And if not, ask away! The more details and context you include, the more likely your question will be selected.
... is no.
The thing you propose sounds fine. But do they really want to upgrade all of the pumps at once? Sounds like a great way to brick an entire facility.
The only "improvement" I could think of would be to set up some kind of cheap router that can do MAC address filtering, that way you can set up the router to allow only one of each pump to show up as that one silly IP address at a time on a switched network. But then you'll still be able to only do one at a time.
The "right" way to do this is just throw money at the problem and attach a real computer to each pump, with a separate interface to talk to the static IP. Maybe something as small as http://www.fit-pc.com/web/prod... or just some generic mini-ITX board in a telecom chassis or whatever.
Get 16 laptops.
Go on FleaBay and get a few older laptops for dirt cheap ; set one up with your software and copy it to all the others.
You can now do thay many pumps at once, and if one has a problem it wont screw up the whole lot.
OP said "day to day" activities. He's updating one pump at a time. What are the other pumps doing? Dispensing gasoline. To update all 16 pumps at once would render all 16 pumps out of service for half an hour. That is simply unacceptable for the station. They would not want to just shut everything down and eliminate a half-hour's worth of revenue from 15 pumps just so OP is not inconvenienced.
This is a typical IT viewpoint. We have a technical problem to solve, and to hell with the users. They're just in the way of our supreme elegance anyway.
How about a moderation of -1 pedantic.
I think you like many are missing the main question and would in fact be the only question I'd ask him and it would determine if you should continue or stop right there.
He offered me a problem, so I offered him a solution. I'm an engineer, I solve problems. He didn't ask for security (which this can be secured by the way, but that involves a bit more discussion, which I don't have enough information to counsel on.)
Are you paid by the hour? If yes, what the actual fuck are you thinking?
Have you ever heard of lean principles? Basically by reducing the number of steps it takes to perform a job, you reduce the chance of human error (thus increasing your product's quality) while also lowering costs. Managers who employ this technique love it when employees make suggestions like this that actually work.
Does his boss appreciate that kind of thing? I don't know, but if I was his boss, and he brought this kind of solution to me, that would gain him some extra brownie points. Instead of having him do that time wasting work, I'd maybe give him better jobs to do that may even pay more, if I had them available.
I think what he's asking is whether or not he can network them together even though they all have the same IP address. And the answer is yes.
As a network engineer, I can think of a way with a Cisco catalyst switch, OR, a linux box with multiple ethernet ports:
Yes, there are a few possible solutions, but I'm surprised that nobody has mentioned the biggest barrier to implementing any of them:
Trying to connect to 8+ pumps at the same time is going to require running 8+ ethernet cables from a central location to each pump. You're going to have cables all over the place, and unless it is done while the gas station is closed it means people driving over the cables, stepping on them, tripping on them and yanking them out of the socket, etc........
As a network engineer, I can think of a way with a Cisco catalyst switch, OR, a linux box with multiple ethernet ports:
That's way too much complication for what he needs.... Assuming each pump has a unique MAC, all you need to do is a bit of work with ARP tables. Collecting MAC's should be easy, cable up and try and ping the standard IP address... They will all reply to the ARP request. Scrape up the MAC's, dump them into his Virtual Machines running the update software to map that MAC to that IP in the VM and make the assignment never expire. Do your update, the software is unlikely to know the difference... For this approach, you only need a switch/hub and network cables.
My other idea was to build a VM box with a separate network segment for each VM, then map these all though a Linux VM that puts them on an 802.1q VLAN. Go buy a *cheap* managed switch (and I do mean cheap) and create one trunk port with each other port on a separate VLAN untagged. No need for an expensive Layer 3 switch... In fact, you could set it up on a cheap consumer router running OpenWRT as long as the switch supports VLANs, in which case the most expensive part of the hardware would be the network cabling..
Although, perhaps the original submitter called them "pumps" rather than "dispenser control heads" because they assumed that was what most /. readers would understand. Generally it's best to communicate in the language your audience understands unless it confuses others -- and you, allegedly knowing how these things work, seem pretty confident that you understood what the submitter meant. Mission accomplished.
Why is there an "insightful" mod and why isn't it "-1"? If I wanted insight, I wouldn't be reading
Sometimes, for diagnostic purposes I also need to add a second read head to the credit card scanner. It would really be helpful if I could add this to the network, along with the keypad's diagnostic port. Any ideas?
In all seriousness though, there are some real fire protection issues with taking cables from the pump zone elsewhere. Everything in and out needs to be properly sealed to prevent explosive vapors from entering into a non spark-resistant system.
I used to work as a field tech, back in the day.
Yeah, "back in the day". Welcome to the new age of gps in trucks, and in company issued phones with fleet tracking.
Using the AC power outlet conveniently located next to the pump? Or that the pumps provide PoE? And, you'll need dongles which retain their configuration and an AP which is configured with a different SSID for each. After that, you still need the switch/NAT stuff which makes it even possible.
Better to simply buy 8 $100 used laptops off eBay, and use one for each pump.
"National Security is the chief cause of national insecurity." - Celine's First Law
There is an answer to this, I've done something similar with security devices. Ideally you would use a hub, if you can still find one, rather than a switch. You'll need the MAC addresses of each pump first, well use 00-12-34-56-78-9A and 00-12-34-56-78-9B. Set a fixed IP address on your laptop, for example 172.16.16.16, and turn off your wireless. Open a command prompt as an Administrator and enter:
arp -s 172.16.16.20 00-12-34-56-78-9A
arp -s 172.16.16.21 00-12-34-56-78-9B
Now your laptop thinks that you have pumps at address 172.16.16.20 and 172.16.16.21. Enjoy your extra time!
"Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin