Unable to trace cables with a Path Split on two sides of a path #10197

Closed
opened 2025-12-29 21:28:05 +01:00 by adam · 3 comments
Owner

Originally created by @derjam on GitHub (Sep 6, 2024).

Originally assigned to: @eriktm on GitHub.

Deployment Type

Self-hosted

NetBox Version

v4.1.0

Python Version

3.12

Steps to Reproduce

We have an Evironment with 40G Switch Ports, which we split up with a cable to 4 x LC Connections. to a patch Panel. On the other side we have the same cable and go from 4 x LC to one 40G Switch Port. I found the error in our self-hosted netbox with a bit more complicated setting. But I was able to reproduce it with the netbox demo environment.

  1. Create a Switch called SwitchA
  2. Create a Switch called SwitchB
  3. Create a Patch Panel called PP1
  4. Create a Patch Panel called PP2
  5. Cable Front Ports 1-4 from PP1 to Front Ports 1-4 to PP2
  6. Cable GigabitEthernet1/0/1 from SwitchA to PP1 Rear Ports 1-4
  7. Cable GigabitEthernet1/0/1 from SwitchB to PP2 Rear Ports 1-4

Expected Behavior

You should be able to do a cable trace.
First you get a Path Split and select one Path:
netbox2
And then you should see the trace:
netbox3

Observed Behavior

You get the Path Split and you can select one Path:
netbox2#
But instead you get a Error, no Path is found:
netbox4

But when you change the connection from one switch interface to only one rear Port on the Patch Panel it works and you are able to trace this connection.

So you go from this:
netbox6
To this setting:
netbox7
It works, you can trace from both directions.

Originally created by @derjam on GitHub (Sep 6, 2024). Originally assigned to: @eriktm on GitHub. ### Deployment Type Self-hosted ### NetBox Version v4.1.0 ### Python Version 3.12 ### Steps to Reproduce We have an Evironment with 40G Switch Ports, which we split up with a cable to 4 x LC Connections. to a patch Panel. On the other side we have the same cable and go from 4 x LC to one 40G Switch Port. I found the error in our self-hosted netbox with a bit more complicated setting. But I was able to reproduce it with the netbox demo environment. 1. Create a Switch called SwitchA 2. Create a Switch called SwitchB 3. Create a Patch Panel called PP1 4. Create a Patch Panel called PP2 5. Cable Front Ports 1-4 from PP1 to Front Ports 1-4 to PP2 6. Cable GigabitEthernet1/0/1 from SwitchA to PP1 Rear Ports 1-4 7. Cable GigabitEthernet1/0/1 from SwitchB to PP2 Rear Ports 1-4 ### Expected Behavior You should be able to do a cable trace. First you get a Path Split and select one Path: ![netbox2](https://github.com/user-attachments/assets/b7ba786a-9235-4d91-b100-c6d0bebd451e) And then you should see the trace: ![netbox3](https://github.com/user-attachments/assets/e5359637-e81d-4e28-9be4-1f02278a1211) ### Observed Behavior You get the Path Split and you can select one Path: ![netbox2](https://github.com/user-attachments/assets/b7ba786a-9235-4d91-b100-c6d0bebd451e)# But instead you get a Error, no Path is found: ![netbox4](https://github.com/user-attachments/assets/b9a37639-599b-4eef-bc21-7bf9a224d025) But when you change the connection from one switch interface to only one rear Port on the Patch Panel it works and you are able to trace this connection. So you go from this: ![netbox6](https://github.com/user-attachments/assets/37f4e60d-939b-49b5-98c3-33bab4fcdd0b) To this setting: ![netbox7](https://github.com/user-attachments/assets/0e404fb5-ad2c-470c-85d4-1c75cf4a0c06) It works, you can trace from both directions.
adam added the type: bugstatus: acceptedtopic: cablingseverity: low labels 2025-12-29 21:28:05 +01:00
adam closed this issue 2025-12-29 21:28:05 +01:00
Author
Owner

@bctiemann commented on GitHub (Sep 6, 2024):

See also https://github.com/netbox-community/netbox/issues/17273 which I closed as a duplicate though it was opened earlier; its repro steps are also valid but are less detailed than in this one.

@bctiemann commented on GitHub (Sep 6, 2024): See also https://github.com/netbox-community/netbox/issues/17273 which I closed as a duplicate though it was opened earlier; its repro steps are also valid but are less detailed than in this one.
Author
Owner

@eriktm commented on GitHub (Oct 9, 2024):

We are also hitting, what appears to be, this same bug. The issue seems to occur when connecting via multiple rear ports with 1 position mapped to 1 front port, and only when the cable trace hits the rear port before hitting the front port.

I already have a possible fix in my test environment, so I can do some more testing and submit a PR on it if thats ok by the maintainers?

@eriktm commented on GitHub (Oct 9, 2024): We are also hitting, what appears to be, this same bug. The issue seems to occur when connecting via multiple rear ports with 1 position mapped to 1 front port, and only when the cable trace hits the rear port before hitting the front port. I already have a possible fix in my test environment, so I can do some more testing and submit a PR on it if thats ok by the maintainers?
Author
Owner

@bctiemann commented on GitHub (Oct 9, 2024):

By all means!

@bctiemann commented on GitHub (Oct 9, 2024): By all means!
Sign in to join this conversation.
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: starred/netbox#10197