[SOLVED] Toner Probe question

pcgamer8084

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Aug 5, 2016
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I have a question about a Toner Probe. Do they work to trace a cable if that the connection between the computer or device that cable is plugged into is separated by say 3 or 4 different switches and cables between each of those 3 or 4 switches andf I am trying to find where one end goes at the ending point past 4 switches and many different network cables, rather than say going just from the back of a patch panel to a wall jack and testing where the cable goes? If I need to clarify what I mean here, please let me know and any help on this is much appreciated.
 
Solution
Its been a while and I forget what solar winds does but that sounds reasonable but if it remember it was expensive.

There are free apps that use SNMP but it doesn't help if all the switches do not support it.

The process is pretty simple. You in effect are doing a form of tracert for mac addresses. You start in some switch and display the mac forwarding table or whatever the switch calls it. There will be a mapping of port number to mac. So lets say you want to find the path between mac address X and mac address Y. Start with a switch that say X is connected to and find the port. You then lookup mac address Y and see what the outbound port is. In complex networks this will go to another switch. So you need a...
I have a question about a Toner Probe. Do they work to trace a cable if that the connection between the computer or device that cable is plugged into is separated by say 3 or 4 different switches and cables between each of those 3 or 4 switches andf I am trying to find where one end goes at the ending point past 4 switches and many different network cables, rather than say going just from the back of a patch panel to a wall jack and testing where the cable goes? If I need to clarify what I mean here, please let me know and any help on this is much appreciated.
Cable tracers only go through passive devices like patch panels. If there are switches, then you would have to trace each cable segment independently.
 
Not really possible that is why documentation on where all the ports on a switch are plugged in is important and docuemtnation on patch panels showing what room each cables goes to. They used to keep all this on the wall of the IDF closets.

If you have fancy managed switches that support SNMP there are many tools that will let you generate diagrams of how things are interconnected and what path a particular pair of mac addresses will take.
 
Not really possible that is why documentation on where all the ports on a switch are plugged in is important and docuemtnation on patch panels showing what room each cables goes to. They used to keep all this on the wall of the IDF closets.

If you have fancy managed switches that support SNMP there are many tools that will let you generate diagrams of how things are interconnected and what path a particular pair of mac addresses will take.
Thanks for the info. I only have 1 fancy managed switch and one basic smart switch as they call it ( basic managed switch) both are 2 buildings apart from each other. The rest of the switches are basic unmanaged switches and they are scattered all over the place, across 3 buildings that are all on the same subnet. I have 1 switch only that supports SNMP. I will look into the tools you mentioned, I know about one's like Solar Winds, is that the kind of one you are referring to? Any suggestions? I have tried to match MAC addresses on devices to the Mac address table in the one managed switch but it is a little tricky looking since with all of the unmanaged switches it shows many devices as being plugged into 1 switch port and it is hard to tell where it goes beyond that. I took over this network after it was already setup years before and the place I work did not have any IT staff before and did not do a good job or any real job in documenting this network. On top of that we only have 1 patch panel and the rest are all just connected to switches mostly unmanaged as I mentioned before. It is really a mess to deal with. It sounds like I really have my work set out for me. Thanks again for the info.
 
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Its been a while and I forget what solar winds does but that sounds reasonable but if it remember it was expensive.

There are free apps that use SNMP but it doesn't help if all the switches do not support it.

The process is pretty simple. You in effect are doing a form of tracert for mac addresses. You start in some switch and display the mac forwarding table or whatever the switch calls it. There will be a mapping of port number to mac. So lets say you want to find the path between mac address X and mac address Y. Start with a switch that say X is connected to and find the port. You then lookup mac address Y and see what the outbound port is. In complex networks this will go to another switch. So you need a list of switches ip/mac addresses also. Best if you have already got the core network done so you know which switches directly connect. You would then log into the next switch in the chain and see what the outgoing port is and continue until you get to a edge port and find the other device.

Many managed switchs have a function similar to cisco CDP neighbor so it is pretty easy to get lists of what switch devices are connected on what ports so you don't have to use the mac address method to get the network interconnection sorted out. All this type of data is also readable via SNMP so many tools like solar winds build the network with this also.

In your case it sounds the like brute force approach. It is not really that hard just very tedious. What you would do is unplug all the end devices from the network. Now with a helper you go jack to jack and plug a pc in. You should only have 1 port light up on the switch. You document that and continue. Key is to not get lazy and not update the documentation as you make changes in the future.
 
Solution
Its been a while and I forget what solar winds does but that sounds reasonable but if it remember it was expensive.

There are free apps that use SNMP but it doesn't help if all the switches do not support it.

The process is pretty simple. You in effect are doing a form of tracert for mac addresses. You start in some switch and display the mac forwarding table or whatever the switch calls it. There will be a mapping of port number to mac. So lets say you want to find the path between mac address X and mac address Y. Start with a switch that say X is connected to and find the port. You then lookup mac address Y and see what the outbound port is. In complex networks this will go to another switch. So you need a list of switches ip/mac addresses also. Best if you have already got the core network done so you know which switches directly connect. You would then log into the next switch in the chain and see what the outgoing port is and continue until you get to a edge port and find the other device.

Many managed switchs have a function similar to cisco CDP neighbor so it is pretty easy to get lists of what switch devices are connected on what ports so you don't have to use the mac address method to get the network interconnection sorted out. All this type of data is also readable via SNMP so many tools like solar winds build the network with this also.

In your case it sounds the like brute force approach. It is not really that hard just very tedious. What you would do is unplug all the end devices from the network. Now with a helper you go jack to jack and plug a pc in. You should only have 1 port light up on the switch. You document that and continue. Key is to not get lazy and not update the documentation as you make changes in the future.

Yeah I got a call awhile ago trying to sell me solar winds, so that is why it was on my mind, but yes it was way too expensive for me to afford. It's nice that there are free alternatives that work with SNMP but yea not all of my switches support it so I have to try another way, but I think as you said I may have to do it more manually, which I agree is not hard just very tedious. I knew I might have to do it that way but wanted to check first if there was another way that was quicker. Once I finally get this done I will make sure to keep up the documentation as the previous staff did not so I came in and it was not documented at all really. The way you mentioned sounds nice, wish it was an option for me right now, but we have a limited budget and just don't have the ability to get all nice switches to make that work, but thanks for that info, very helpful to know.