How to tell which ports are open or in use?

What works, and doesn't, for you. Be specific, and please include Puppy version.
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gcmartin

#31 Post by gcmartin »

We'd like to help, but, there seems to be something that is missing in what you share.

Here's my understanding problem:
  • You say the printer can be ping'd and you say that the printer's webpage can be accessed by your customer. True/false?
  • You say you are using a cross-over cable. Why are you using a cross-over? Are you not able to use your customer's LAN?
  • You never mentioned if you could utilize the customer'sprinter from your PC. Can you print?
  • You don't mention whether the customer has other printers present. Do they and can they print? If so, are any of the present printers the same character as this printer?
My external concern is whether you have sold your customer a device for which your customer does NOT have a broken printer. (I've seen this before, too. And, hopefully, this is not the case.)

Questions
What OS is your customer running? And, can you run the same? If you cannot use your customer's PC, then you need to memic the problem by installing a similar OS on your PC to follow thru on testing.
Also, you mention Citrix. What exactly is your customer printing from?

Should you do capture packets, unless you have been trained on understanding printer languages, I'm not sure how that will help you...asuming you are successful.

Can you provide a bit more clarity on top of what you've already shared?

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greengeek
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#32 Post by greengeek »

gcmartin wrote:We'd like to help, but, there seems to be something that is missing in what you share.

Here's my understanding problem:[*]You say the printer can be ping'd and you say that the printer's webpage can be accessed by your customer. True/false?
True on both counts.
[*]You say you are using a cross-over cable. Why are you using a cross-over? Are you not able to use your customer's LAN?
Correct - I can not risk connecting my laptop to the customers network at this stage. (maybe later if I have their permission)
[*]You never mentioned if you could utilize the customer'sprinter from your PC. Can you print?
Yes, I can print to the customers printer from my PC (via crossover cable)
[*]You don't mention whether the customer has other printers present. Do they and can they print? If so, are any of the present printers the same character as this printer?
They have no other printers available on this site, however they say they have a number of these printers running correctly on other sites around the city. They say this printer did work correctly for a week before it went "offline" and stopped printing.
My external concern is whether you have sold your customer a device for which your customer does NOT have a broken printer. (I've seen this before, too. And, hopefully, this is not the case.)
Not sure what you mean by this.
Questions
What OS is your customer running?
The IT contractor was unable to tell me. He told me that their IT managers had demanded we supply a new printer as "there was nothing wrong with their network".
Also, you mention Citrix. What exactly is your customer printing from?
They won't (yet) tell me what they are running. I am guessing that they may be running Citrix as this type of problem with printers dropping off the print subsystem seems common on Citrix systems - firstly becase Citrix seems to add another level of configuration/complexity and secondly because Citrix administrators seem unwilling (or perhaps incompetent) to investigate problems deeply. In my experience they tend to keep changing printers till they find one that luckily happens to work with their system.
Should you do capture packets, unless you have been trained on understanding printer languages, I'm not sure how that will help you...asuming you are successful.
I'm hoping to trap a text file of packets that carry the IP of this printer and see if they offer any clues about whether or not fresh data comes down to the printer when a print job is triggered. Even if I can't decipher each packet I feel I should be able to gauge roughly what is happening when.

Some of the people I have spoken to today suggest I need to use Wireshark, so I will research this further.
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musher0
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#33 Post by musher0 »

Hello, greengeek and the bunch.

This topic was also answered, last month I believe, from the angle of compiter security, here :
http://murga-linux.com/puppy/viewtopic. ... 5&start=15

Just follow the discussion for lsof on that page.

musher0
musher0
~~~~~~~~~~
"You want it darker? We kill the flame." (L. Cohen)
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gcmartin

#34 Post by gcmartin »

greengeek wrote:
gcmartin wrote:You say you are using a cross-over cable. Why are you using a cross-over? Are you not able to use your customer's LAN?
Correct - I can not risk connecting my laptop to the customers network at this stage. (maybe later if I have their permission)
gcmartin wrote:You never mentioned if you could utilize the customer's printer from your PC. Can you print?
Yes, I can print to the customers printer from my PC (via crossover cable)
gcmartin wrote:Should you do capture packets, unless you have been trained on understanding printer languages, I'm not sure how that will help you...asuming you are successful.
I'm hoping to trap a text file of packets that carry the IP of this printer and see if they offer any clues about whether or not fresh data comes down to the printer when a print job is triggered. Even if I can't decipher each packet I feel I should be able to gauge roughly what is happening when.

Some of the people I have spoken to today suggest I need to use Wireshark, so I will research this further.
OK, here my accessment from what you share.

I am still confused when you share that you cannot connect your PC to the customer's LAN ??? But can connect your printer to his LAN. Further, when you share Wireshark and other LAN test tools how do you intend to connect for observation? Be aware, you are at a distinct disadvantage since you are not capable of using your machine that you have already tested with.

Aside from that
You do NOT have a printer problem based upon your cross-over cable work and the fact that your customer can access the new printer's webpage.

If you know a little about priner setup, you may want to follow these instructions:
  1. Power up the old printer
  2. Use your cross-over cable to connect to its webpage
  3. You MAY want to test to see if you can print to it (Get back to me if you can print to it)
  4. Write down its MAC address AND its LAN address
  5. Power up the new printer
  6. Use your cross-over cable to connect to its webpage
  7. Set the new printer's MAC address AND its LAN address to match the old printer.
  8. Connect the new printer to the LAN
  9. Insure that your customer can connect to tts webpage
  10. Print. (This assumes the PC's OS has the correct Printer driver.)
Lastly, you may want to change this thread's title as it appears more about Printer problem than about LAN/WAN ports

Also be aware that you could be looking at a PC printer driver problem or you "may" have some sort of a LAN security problem in play.

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greengeek
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#35 Post by greengeek »

gcmartin wrote: Lastly, you may want to change this thread's title as it appears more about Printer problem than about LAN/WAN ports
Thanks GC, yes my questions have strayed off the original topic so I will not post further here. I will do further research about the methods (hardware and software) that will allow me to tap the cable to the printer and extract the data packets. If I have any info/clarification/solutions I will begin a new thread. Thanks all for the help.

EDIT: Just one last note:
I am still confused when you share that you cannot connect your PC to the customer's LAN ??? But can connect your printer to his LAN. Further, when you share Wireshark and other LAN test tools how do you intend to connect for observation
I think maybe I was not clear enough about the printer: It is not my printer - it is the customer's printer but they bought it (brand new) from the company I work for. I cannot connect my PC to their LAN for security reasons. However, with their future permission I should be able to connect my PC to the Rx pair in the cable to the printer (so that my PC is only "listening" to the data packets and cannot respond). Information I found on google suggests I can make a "passive network tap" which will attach to the rx wires without interrupting the connection between the printer and router. Then I will use wireshark and/or peasyscan etc to evaluate what data activity is occurring on the interface to the printer. Hopefully.

If successful I will detail this in a new thread.
.
Last edited by greengeek on Mon 14 Jan 2013, 19:18, edited 1 time in total.
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rcrsn51
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#36 Post by rcrsn51 »

Here is a really simple test. Send a job to the printer and watch for the Ethernet port indicator lights to start blinking.
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greengeek
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#37 Post by greengeek »

My understanding is that the port lights can blink for many reasons other than an incoming data packet - for example I believe routers can issue periodic automatic pings etc. I'm just hoping to be able to trap a distinguishable data packet that convinces me beyond doubt that it is actual valid data that is reaching the printer, not just a "control" packet.

On some networks I see port lights flashing very quickly - even when there is no active print job at all.
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