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Aruba ClearPass Enforcement Miss: Access Tracker When the Switch Ignores the VLAN

  • 3 days ago
  • 2 min read
Aruba ClearPass network security troubleshooting lab
Aruba ClearPass · Techclick CLI troubleshooting lab
ClearPass Access Tracker shows accept and VLAN 40. The Aruba/Cisco switch still has the endpoint in VLAN 1.

This is a live-ticket style lesson from Techclick Infosec. You will isolate the fault with CLI first, then prove the fix with one clean packet or log.

What you will be able to do

  • Name the first CLI command to run on Aruba ClearPass for this ticket

  • Separate the layer that is actually broken from the layer people blame

  • Apply one scoped fix instead of a global disable

  • Prove the ticket closed with a session, log, or counter

Quick answer

Accept is RADIUS. The switch must apply the RFC 2868 attributes. Wrong dictionary or a local override leaves VLAN 1.

Why this ticket shows up

ClearPass cannot change a port the NAD refuses to honor. Tracker looking green is not the data plane.

Symptoms operators actually see

  • Tracker accept, VLAN 1

  • Missing Tunnel-Private-Group-Id

  • Local VLAN on the port

  • Wrong NAD dictionary

CLI first — copy this block

Run these on the Aruba ClearPass device or console named in the ticket. Do not skip the first show command — it tells you which later command matters.

show aaa authentication port-access interface 1/1/1
show port-access clients 1/1/1
show running-config interface 1/1/1
# or Cisco:
show authentication sessions interface Gi1/0/7 details

How to read that output

The live session must list VLAN 40. If Tracker sent 40 and the switch shows 1, the attribute was ignored or overridden.

Triage order

  1. Open Access Tracker and read sent attributes

  2. On the switch, read the live session VLAN

  3. Remove static VLAN / auth-fail VLAN conflicts

  4. Fix the dictionary if the attribute is missing

  5. Reauth the port

Classic traps

What you see

Real cause

Fix

Rewrite the whole ClearPass service

Switch has a static VLAN

Remove it

Disable 802.1X

One interface override

Fix that port

Trust Tracker only

Data plane is the switch

Read the port

Proof the ticket is closed

  • Switch session VLAN 40

  • Client gets the 40.x address

  • Tracker and port agree

Say this in an interview

I compare ClearPass sent attributes to the switch session. Accept is not enforcement.

Need the full vendor lab, mock interview, and production runbooks? Techclick trains Palo Alto, Zscaler, F5, FortiGate, Check Point, Cisco ISE, Azure and routing with live CLI — start at https://www.techclick.in/

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