- Overview
- Product Documentation
- CML 2.6 Release Notes
- CML 2.6 Installation Guide
- CML 2.6 User Guide
- CML 2.6 Admin Guide
- CML Administrator's Guide
- Cisco Modeling Labs System Overview
- System Defaults
- Creating a New Node Definition
- Custom VM Images
- Clustering
- CML Admin Tools
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- Networking
- Resources
Example: External Connector on System Bridge¶
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.
For another example, the third-party software running the WAN Emulator node, when connected to the same bridge with multiple interfaces, will flood the interfaces with IGMP group join messages, which can disrupt access to the CML UI and prevent users from stopping the node or links.
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
Add a new lab in the Dashboard. The view will switch to the created lab’s Workbench view.
Optional: Give the new lab a name by clicking the date-based title at the top of the workbench, editing the Title text field and clicking the Apply checkmark button to its side. Example: bridge_connector.
Open the Add Nodes pane from the top toolbar. Drag-and-drop all required nodes onto the canvas.
Connect ext-conn 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 Config tab in the sidebar pane.
Change the value of the selected external connector dropdown to System Bridge mode.
Optional: Click the Lab -> Bootstrap Lab menu in the top toolbar.
This action provides a basic configuration including a system-assigned
username and password of cisco/cisco to the Cisco routers in the
lab. You could also edit each node’s configuration for OOB management,
to e.g., use an external DHCP service provided on the network, or use manual
configuration on the interfaces connected to the bridge.
This example will add the configuration to the running nodes later.
Click the Lab -> Start Lab menu in the top toolbar.
The system will start a lab simulation, and the node VMs will start booting.
Wait for all nodes to finish booting, indicated by a green checkmark on the node.
Once all nodes have booted, you still need to configure each node for
OOB management, or verify the edited bootstrap configuration was effective.
This example will show how to configure basic connectivity using a VRF
for management and routing on interface gi0/0.
Right-click the IOSv node and click the Console menu.
Click the Open Console button in the Console pane that appears.
Log in.
Use the credentials that you set in the initial configurations for the devices. | Username: cisco | Password: cisco
Add a VRF configuration 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.