Cisco released an update to VIRL which is rebranded as CML (Cisco Modeling Labs). I decided to give CML-P a try by deploying the VMware OVA.

Intrigued by the External connector because of Python scripting and automation purposes, I wanted to connect my images to my own network.

But I was unable to get ping, ssh, and other services to go through my external connector. I reconfigured switch ports as trunk and access modes, verified my default gateway, default route, and more.

In the end, it had to do with how VMware ESXi (v6.7 in my lab) vSwitch handles traffic.

Under the Security settings of my ESXi vSwitch0 I need to accept Promiscuous mode and Forged transmits. I’d also enable MAC address changes.

These settings should be enabled for the virtual devices to work properly in CML-P.

Promiscuous mode is disabled by default and it would allow VMs on the vSwitch to monitor traffic.

MAC address changes is also disabled by default. I enabled this setting just in case the MAC address changes for my various simulated devices on CML-P.

Forged transmits is disabled by default and will need to be set to Accepted for management traffic to work properly to your simulated devices.

Hopefully I saved you some headache in getting started with your labs using Cisco CML-P.

VMware vSwitch0 configuration