Find where a Pending Node (Leaf) is physically connected (no LLDP)?

[vv0bbLeS]

Hello all,

I inherited an ACI fabric that is running 4.0(2c) (and yes I am planning an upgrade to 5.2 as 4.0 is EOL). I'm trying to figure out where all the leafs are in the datacenter without having to look in every rack.

The 14 Leafs that are already joined to the fabric are easy as they have the rack name in the leaf name, so no problem there.

In my APIC GUI > Fabric > Fabric Membership > Nodes Pending Registration, I show a count of 9 Nodes Pending registration, so 9 leafs not joined to the fabric. So I need to figure out where these are located in the datacenter.

I thought it would be easy enough to simply login to a Spine and run show lldp neighbor and then see what port on the Spine the 9 generic "switches" are connected to, and then just look at the cable labels / trace the cables.

However, when I run that show lldp neighbor command on both Spines, I see all 14 of my registered Leafs of course, but I only show 7 "generic switches" connected, instead of the 9 that I would expect (as it showed 9 "Nodes Pending Registration" in the GUI).

So I guess my questions are:

1. How could a Leaf show up in Nodes Pending Registration, but not show up in the Spines' LLDP neighbors?
2. Is there another way to tell where a "discovered" Leaf is connected to the fabric?

[naveeku6 · Accepted solution]

One possible reason that a Leaf could show up in Nodes Pending Registration but not show up in the Spines’ LLDP neighbors is that the Leaf may not be physically connected to the Spine or may not be powered on. You could try checking the physical connections and power status of the Leafs to see if this is the case.

Another way to tell where a “discovered” Leaf is connected to the fabric is by checking the Leaf’s logs for any information about its connection to the fabric. You could also try checking the switch port status on the Spine to see if there are any ports that are administratively up but operationally down, which could indicate a disconnected Leaf.

If you continue to have difficulty locating the Leafs, you may want to consider opening a support case with Cisco for further assistance.

[vv0bbLeS]

@naveeku6 thanks for the reply! Yes I had already seen a few "notconnect" ports on the Spine, so going to have someone at the site investigate those to see if that's where the 2 mystery Leafs are located. And yes good point about the Leafs maybe not being connected to the Spines. One question - where are the leaf logs located that you spoke of? I'm assuming on the Leaf itself but do you have the file path to the logs?

Also, once I figure out the physical connection situation for these 2 mystery Leafs I will try to remember to update this thread. Thanks again!

[naveeku6]

@vv0bbLeS , Thanks for accepting as solution.

In an ACI fabric, you can check the Leaf logs to troubleshoot issues related to connectivity or configuration. Here are some steps you can take to access the Leaf logs:

1. Log in to the APIC controller GUI.
2. Navigate to the Fabric > Inventory > Fabric Membership page.
3. Select the Leaf that you want to troubleshoot and click on the “Logs” button.
4. You can then view the various logs related to the selected Leaf. The most common logs that you might want to check are the System, Ethernet, and LLDP logs.
5. Look for any error messages or warnings in the logs that might indicate connectivity or configuration issues.

If you are comfortable with using the CLI, you can also access the Leaf logs using the following steps:

1. Log in to the APIC controller CLI.
2. Use the “topology” command to display the current topology of the fabric.
3. Identify the Leaf that you want to troubleshoot and note its node ID.
4. Use the “fabric” command to access the CLI for the selected Leaf.
5. Use the “show logging log” command to display the various logs for the selected Leaf.
6. Look for any error messages or warnings in the logs that might indicate connectivity or configuration issues.

[vv0bbLeS]

@naveeku6 great, thanks for your reply! I am unable to find the logs in the GUI as you specified above. I am running version 5.2(7g).

• If I select a Leaf on the Fabric Membership page, and right-click it, I don't see any Logs option.
• If I double-click a Leaf on the Fabric Membership page, I can see the standard Audit Logs or History tabs, but no specific "Logs" like LLDP or Ethernet.

Could you include a screenshot of where you're seeing the "Log" button at? Or perhaps this is a feature in the new 6.0 software train?

Also, I could not get the topology command to work on my APIC CLI. I can use the standard acidiag fnvread or show switch commands. What version are you running where you can run the topology command?

Thanks!

[naveeku6]

@vv0bbLeS , I am running 5.2(1g) in the lab and tried these steps.

In GUI , Go to Fabric -> Inventory, then choose the leaf and  Click the History and you can see all faults, event and health.

In CLI, You can use "show events" command and check for your Node name in the events , it will dispaly the cause and reason for port failure for the Node.

[vv0bbLeS]

@naveeku6  OK great! Thanks again!