Fix Cisco ISE Node Traffic Not Flowing in PNET-Lab

Introduction

A common issue when installing a Cisco ISE node in PNET-Lab is that the node powers on and runs fine, but traffic simply doesn't flow out of it. Before assuming it's a configuration problem inside ISE itself, check the underlying virtual hardware settings PNET-Lab assigns to the node, in most cases that's the actual cause.

Why This Happens

The Cisco ISE node needs a specific Qemu version and a specific NIC (network interface card) type to work properly inside a lab environment. If the node is left on its default Qemu and NIC settings, the virtual network interface doesn't behave the way ISE expects, and traffic fails to pass through even though the node itself appears to be running normally.

Fixing the ISE Node Settings

Follow these steps to correct the Qemu and NIC settings for your ISE node.

Step 1 – Power Off the ISE Node

Before changing any hardware settings, the ISE node must be powered off cleanly from inside the node itself, not just stopped from the PNET-Lab topology view.

application stop ise

halt

Confirm the prompt to proceed with the shutdown.

Step 2 – Set the Correct NIC and Qemu Version

Once the node is fully powered off, open its settings in PNET-Lab and update the following values:

Save the settings and power the ISE node back on. Traffic should now flow correctly through the node's interface.

Conclusion

If a Cisco ISE node in PNET-Lab isn't passing traffic, it's worth checking the Qemu and NIC settings before troubleshooting further inside ISE itself. Setting the NIC to virtio-net-pci and the Qemu version to 3.1.0 resolves this issue in most lab setups.