Cannot get a full Cable Trace anymore

[r0bc94]

Hi,

I have a switch which is attached to an IP telephone. The connection looks as follows:

• Telephone goes to a Wall Box
• The Wall Box goes to a rear port of a patch panel
• The front port of he patch panel terminates on a switch

The issue is that I am not able to see a full trace for whatever reason. When checking the trace from the telephone interface, the trace graph ends at the Path panel. There is no connection between the front port of the patch panel to the switch.

When now checking this from the other side, the trace ends on the network box, but there is not connection between the box and the telephone.

I actually see that netbox detected something, as the telephone path is marked as a related path. But I cannot get my head around on what I did wrong here. I also checked the assignment between the front and rear ports but it looks correct. Maybe I did something wrong when creating the interfaces?

[pheus]

Hi @r0bc94,

To help troubleshoot this, could you share a bit more information about how this is modeled?

• Which NetBox version are you running?
• Are any plugins installed? If so, which ones and what versions?
• If this started recently, did it begin after an upgrade? If so, from which version?
• How is the front port mapped to the rear port, including any position mapping?
• What are the exact terminations at each step in the path? A couple of screenshots of the relevant front ports, rear ports, mappings, and cables would also be very helpful.

If you have not already tried it, it would also help to model the same scenario in a fresh environment or on the public demo site. If you can reproduce the same behavior there, please share the exact steps you followed so others can try to reproduce it as well.

That should give everyone a much better chance of seeing whether something is off in how the path is modeled, or whether you may have found a bug.

[r0bc94]

Which NetBox version are you running?

v4.4.8

Are any plugins installed? If so, which ones and what versions?

If this started recently, did it begin after an upgrade? If so, from which version?

To be fair, we did not upgrade in between. Im not sure if maybe the interface definition on the telephone is the issue? I set it to be a POE powered device.

How is the front port mapped to the rear port, including any position mapping?

The Front to back mapping is basically 1:1. For example:

• Front Port 1 -> Rear Port 1
• Front Port 2 -> Rear Port 2
• ...

I can check to include the device definition in the demo environment.

[r0bc94]

I was able to also reproduce this issue in the Demo environment:

As you can see, I have the following devices:

• The Telephone named Phone
• The Patch Panel in between named PatchPanel A
• The Cisco Switch at the other end named Cisco01

You can also see that the path is incomplete, for whatever reason. Maybe this gives you a better hint on what I did wrong here.

[pheus]

Hi @r0bc94,

thanks for the additional details and for reproducing this in the demo environment.

You did confirm that there was no upgrade in between, so thank you for that. What is still unclear, though, is this part: when you say "Cannot get a full Cable Trace anymore", do you mean that this used to work in the same environment? If yes, then something must have changed, so it would be helpful to know what changed.

From what you have shown so far, the most important part to verify is the front-to-rear mapping. That is the most likely reason for the incomplete trace. Could you please share screenshots of the specific front port and rear port configuration on the patch panel, including the mapping fields?

Regarding the demo environment: unfortunately, I can no longer inspect the exact setup because the demo data has already changed. However, the DeviceType Generic Patchpanel Kupfer 24 Port is still there. In that DeviceType, you created 24 rear ports of type 8P8C and 24 front ports of type 8P8C, but the front ports do not appear to be mapped to the corresponding rear ports.

That mapping is essential. Without it, NetBox does not know which front port maps to which rear port, so the cable trace stops at the patch panel instead of continuing through it.

I added the mapping for the first front port to the first rear port and attached a screenshot for reference. For a 1:1 setup, it should look like this:

• Front Port 1 → Rear Port 1 (I've added that for reference)
• Front Port 2 → Rear Port 2 (Here it is missing)
• and so on

Note: The demo site data is reset every day.

[r0bc94]

Hi

You did confirm that there was no upgrade in between, so thank you for that. What is still unclear, though, is this part: when you say "Cannot get a full Cable Trace anymore", do you mean that this used to work in the same environment? If yes, then something must have changed, so it would be helpful to know what changed.

When I created such links in the past, it works as expected. However, there was no device using PoE in the past so maybe this might be a factor?

From what you have shown so far, the most important part to verify is the front-to-rear mapping. That is the most likely reason for the incomplete trace. Could you please share screenshots of the specific front port and rear port configuration on the patch panel, including the mapping fields?

Where can I configure such mapping other than in the front port configuration? In our lab, the Mappings looks like so:

To me this looks correct and I do not know where I could specify such mappings. However, in your screenshot there is the colon in the mapping column which is missing in our case.