External Connector - Bridge Mode

Bridge mode provides an unrestricted layer-2 connection to networks outside of the CML virtual environment. Standard networking rules apply. You must provide the required networking configuration on all simulation nodes that have been connected to the external network.

Caution

It is possible for you to cause disruption on your real network or to trigger a loss of access to the CML server when you simulate a lab that uses bridge mode on an external connector. For example, ports on IOSv-L2 nodes are L2 by default with PVST STP and auto-negotiation for trunking enabled. If your topology has such an L2 device configured in switch-mode and if one of the switch ports is in the same broadcast domain as the external connector’s port, when the L2 port comes up, it will transmit BPDUs that can trigger either an err-disable on an upstream switchport or a spanning tree event that can cause wider network disruption.

In this example, out-of-band (OOB) management connectivity is provided to multiple nodes using a single ext-conn node and leveraging an Unmanaged Switch.

Use Case	Provide layer-2 access to the simulation from the external network OOB (out of band) management of simulated devices.
Topology	IOSv router connecting an IOSv-L2 switch
Required Nodes	External Connector (×1) Unmanaged Switch (×1) IOSv (×1) IOSvL2(×1)

Procedure

---

Create a new lab in the Dashbaord.

Optional: Give the new lab a name. Example: bridge_connector.

Click the bridge_connector lab tile to open the Workbench.

Drag-and-drop the required nodes onto the topology canvas.

Connect ext-connB to unmanaged-switch.

Connect the iosv and iosvl2 nodes to unmanaged-switch using gi0/0 to any port on the unmanaged-switch.

Select the ext-conn node.

Click the Edit Config tab in the bottom pane.

Click Bridge in the Edit Config pane to select bridge mode.

Press the ESC key to deselect the ext-conn node.

Optional: Click the Design tab in the bottom pane.

Optional: Click Build Initial Bootstrap Configurations in the Design

pane.

This action provides a basic configuration and a system-assigned username and password of cisco/cisco to the Cisco routers in the lab.

Click the Simulate tab in the bottom pane.

Click Start in the Simulate pane.

The system will start a lab simulation, and the node VMs will start booting.

Wait for all nodes to finish booting.

Once all nodes have booted, you still need to configure each node for OOB management. This example will show how to configure basic connectivity using a VRF for management and routing on interface gi0/0.

Select the IOSv node.

Click the Console tab in the bottom pane.

Click the Open Console button in the Console pane.

Log in.

Use the credentials that you set in the initial configs for the devices. | Username: cisco | Password: cisco

Add a VRF config to the node.

Sample VRF config:

enable
conf t
vrf definition Mgmt-intf
address-family ipv4
int gi0/0
ip address n.n.n.n m.m.m.m (IP address and subnet mask)
exit
ip route vrf Mgmt-intf 0.0.0.0 0.0.0.0 g.g.g.g (source destination gateway)

For each node that requires OOB management to the bridged network, add a VRF configuration by repeating the steps from Step 16 to Step 20.

---