# Select additional options for Virtual Engine interfaces

In the Virtual Engine's interface options, you can select which IP addresses are used in particular roles.

##

Interface Options can only be configured for Virtual Engines. All communication between Virtual Engines and the SMC is proxied by the Master Engine. Virtual Engines do not have any interfaces for system communication.

For more details about the product and how to configure features, click Help or press F1.

## Steps

1. Right-click a Security Engine, then select Edit <element type>.
2. Browse to Interfaces > Interface Options.
3. Configure the settings.

## Next steps

Continue the configuration in one of the following ways:

- Add loopback IP addresses for the Virtual Engine.
- If you are configuring a new Virtual Engine, click Save, close the Engine Editor, then add routes for the Master Engine.
- Otherwise, click Save and Refresh to transfer the configuration changes.

## Engine Editor > Interfaces > Interface Options

Use this branch to define which IP addresses are used in particular roles in the Security Engine's system communications.

Option | Definition
--- | ---
Control Interface (Not Virtual Engines) | Primary — Specifies the Primary Control IP address for Management Server contact. Backup (Optional) — Specifies the Backup Control IP address that is used if the Primary Control IP address is not available. Note: We recommend that you do not use the IP address of an Aggregated Link interface as the primary or secondary control IP address of the Engine.
Node-Initiated Contact to Management Server | When selected, the Security Engine opens a connection to the Management Server and maintains connectivity. This option is always used with a dynamic control IP address, so it is always selected if the control IP address is dynamic. If the connection is not open when you command the Security Engine through the SMC Client, the command is left pending until the Security Engine opens the connection again. Note: This option is not supported for IPS Clusters, Layer 2 Engine Clusters, or Virtual Security Engines.
Heartbeat Interface (Clusters and Master Engines only) | Primary — Specifies communications between the nodes. We recommend that you use a Physical Interface, not a VLAN Interface. We strongly recommend that you do not direct any other traffic through this interface. A dedicated network helps guarantee reliable and secure operation. CAUTION: Primary and Backup Heartbeat networks exchange confidential information. If dedicated networks are not possible, configure the cluster to encrypt the exchanged information. Backup — Used if the Primary Heartbeat Interface is unavailable. It is not mandatory to configure a backup Heartbeat Interface, but we strongly recommend it. If heartbeat traffic is not delivered, the cluster cannot operate and traffic is interrupted. We strongly recommend that you use a dedicated interface for the backup heartbeat as well. On Master Engines, you cannot use shared interfaces as a heartbeat interface.
IPv4 Identity for Authentication Requests or IPv6 Identity for Authentication Requests | The IPv4 address or IPv6 address of the selected interface is used when an Security Engine contacts an external authentication server. This option does not affect the routing of the connection with the authentication server. The IP address is used only as a parameter inside the authentication request payload to give a name to the request sender.
IPv4 Source for Authentication Requests or IPv6 Source for Authentication Requests | By default, specifies the source IPv4 address or IPv6 address for authentication requests according to routing. If the authentication requests are sent to an external authentication server over VPN, select an interface with a Node Dedicated IP address that you want to use for the authentication requests.
Default IP Address for Outgoing Traffic | Specifies the IP address that the Security Engine uses to initiate connections (such as for system communications and ping) through an interface that has no Node Dedicated IP Address. In clusters, you must select an interface that has an IP address defined for all nodes.