# Add physical interfaces for Master Engines

In addition to physical interfaces that are used for hosted Virtual Engine communications, you must add at least one physical interface for system communications.

##

The types of interfaces that you can configure for the Master Engine depend on the role of the Virtual Engines that the Master Engine hosts. For Master Engines that host Virtual Engines, you can add Layer 3 physical interfaces and Layer 2 physical interfaces.

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.
3. Depending on the role of the hosted Virtual Engine, select Add > Layer 3 Physical Interface or Layer 2 Physical Interface.
4. Configure the settings, then click OK.

## Layer 3 Physical Interface Properties dialog box (Master Engine and Virtual Engine)

Use this dialog box to define the Layer 3 Physical Interface properties for a Master Engine in the Engine/VPN role or a Virtual Engine.

Note: The available options can vary depending on the type of Security Engine, whether an interface is layer 2 or layer 3, and the type of layer 2 interface.

Option | Definition
--- | ---
General tab
Interface ID | The Interface ID automatically maps to a physical network port of the same number during the initial configuration of the engine. The mapping can be changed as necessary through the engine’s command line interface. Note: Changes to the Master Engine interface mapping do not affect the Interface IDs that are defined for Virtual Engines in Virtual Resource elements.
Type | None — Corresponds to a single network interface on the Engine. Aggregated Link in High Availability Mode — Represents two interfaces on the Engine. Only the first interface in the aggregated link is actively used. The second interface becomes active only if the first interface fails. Connect the first interface to one external switch and the second interface to another external switch. Note: When you select a Virtual Resource for an interface in the Master Engine, two Physical Interfaces are created in the Virtual Engine properties. Each interface in the aggregated link interface pair is represented by a separate Physical Interface in the Virtual Engine properties. Aggregated Link in Load Balancing Mode — Represents up to eight interfaces on the Engine. The interfaces in the aggregated link are actively used and connections are automatically balanced between the interfaces. This mode is implemented based on the IEEE 802.3ad Link Aggregation standard. Connect the interfaces to a single external switch. Make sure that the external switch supports the Link Aggregation Control Protocol (LACP) and that LACP is configured on the switch. 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.
Second Interface ID | (When Type is Aggregated Link in High Availability Mode) The second interface in the aggregated link for high availability Mode.
Additional Interface(s) | (When Type is Aggregated Link in Load Balancing Mode) Lists interfaces that you have added for an aggregated link. Click Add to add a row to the table, or Remove to remove the selected row.

Option | Definition
--- | ---
Virtual Resource section (Master Engines only)
Virtual Resource | The Virtual Resource associated with the interface. Select the same Virtual Resource in the properties of the Virtual Engine to add the Virtual Engine to the Master Engine. If the interface is to be used for the Master Engine system communications, select None. For Master Engines that host Virtual Engines, you can select Multiple Virtual Resources to allow several Virtual Engines to share a single physical interface. To add multiple Virtual Resources for Virtual IPS engines or Virtual Layer 2 Engines, add VLAN Interfaces to the Physical Interface, then select a Virtual Resource in the properties of each VLAN Interface.
Allow VLAN Definition in Virtual Engine | (When the Virtual Resource option is a single Virtual Resource) When selected, you can add VLAN Interfaces to the automatically created physical interfaces in the Virtual Security Engines that are associated with this interface.
Virtual Engine Interface ID | (When the Virtual Resource option is a single Virtual Resource) Specifies the Interface ID of the Physical Interface in the Virtual Engine that is associated with this interface.
Cluster MAC Address | (When the Virtual Resource option is a single Virtual Resource) Specifies a MAC address for the Master Engine. Do not use the MAC address of any actual network card on any of the Master Engine nodes.
Interface Throughput Limit | (When the Virtual Resource option is a single Virtual Resource) Enter the throughput for the link on this interface as megabits per second. If the Virtual Resource element has a limit defined, the limit defined in that element is always used.
Virtual Resources table | (When the Virtual Resource option is Multiple Virtual Resources) Select the Virtual Resources that you want to use for the associated Virtual Engines. Click Add to add an element to the table, or Remove to remove the selected element.
Virtual Resource | The selected Virtual Resource element.
Interface ID | Specifies the Interface ID of the Physical Interface in the Virtual Engine that is associated with this interface.
Throughput Limit | Enter the throughput for the link on this interface as megabits per second. If the Virtual Resource element has a limit defined, the limit defined in that element is always used.
MAC Address Prefix | (When the Virtual Resource option is Multiple Virtual Resources) Enter a unique unicast MAC address prefix (the first five octets of a MAC address) that identifies the interface and groups the Virtual Engines that use this interface. Each individual Virtual Engine is identified by a full unique unicast MAC address (the prefix and the final octet which is taken from the Virtual Engine ID).

Option | Definition
--- | ---
Interface Settings for Master Engine section (Master Engines only) The options in this section apply only to the Master Engines system communications.

Option | Definition
--- | ---
Zone (Optional) | Select the network zone to which the interface belongs. Click Select to select an element, or click New to create an element.
QoS Mode (Optional) | Select the QoS mode to apply to the link on this interface. You can select from one of the following options: No QoS: When selected, no QoS mode is enabled. QoS Statistics Only: It allows the collection of QoS Class-based counters without activating any other QoS feature. DSCP Handling and Throttling: When selected, no queues and no throttling of all traffic. Only the connections that are tagged with QoS Class are treated as per the action that is defined in the QoS policy. Full QoS: It throttles all traffic to the Interface Throughput Limit that is set in the interface properties Note: If Full QoS or DSCP Handling and Throttling is selected, a QoS policy must also be selected. If Full QoS is selected, the throughput must also be defined. If the interface is a Physical Interface, the same QoS mode is automatically applied to any VLANs created under it.
QoS Policy | (When QoS Mode is Full QoS or DSCP Handling and Throttling) The QoS policy for the link on this interface. If the interface is a Physical Interface, the same QoS policy is automatically selected for any VLANs created under it. Note: If a Virtual Resource has a throughput limit defined, the interfaces on the Virtual Engine that use a QoS policy all use the same policy. The policy used in the first interface is used for all the interfaces.
Interface Throughput Limit | (When QoS Mode is Full QoS) Enter the throughput for the link on this interface as megabits per second. If the interface is a Physical Interface, the same throughput is automatically applied to any VLANs created under it. The throughput is for uplink speed (outgoing traffic) and typically must correspond to the speed of an Internet link (such as an ADSL line), or the combined speeds of several such links when connected to a single interface. CAUTION: Make sure that you set the interface speed correctly. When the bandwidth is set, the Engine always scales the total amount of traffic on this interface to the bandwidth you defined. This scaling happens even if there are no bandwidth limits or guarantees defined for any traffic. CAUTION: The throughput for a Physical Interface for a Virtual Engine must not be higher than the throughput for the Master Engine interface that hosts the Virtual Engine. Contact the administrator of the Master Engine before changing this setting.

Option | Definition
--- | ---
MTU (Optional) | The maximum transmission unit (MTU) size on the connected link. Either enter a value between 400–65535 or select a common MTU value from the list. If the interface is a Physical Interface, the same MTU is automatically applied to any VLANs created under it. The default value (also the maximum standard MTU in Ethernet) is 1500. Do not set a value larger than the standard MTU, unless you know that all devices along the communication path support it. To set the MTU for a Virtual Engine, you must configure the MTU for the interface on the Master Engine that hosts the Virtual Engine, then refresh the policy on the Master Engine and the Virtual Engine.
LLDP Mode | Specifies how LLDP is used on the interface. Disabled — LLDP is not used. Receive Only — The interface only receives LLDP announcements from other directly connected devices in the network. Send and Receive — The interface sends LLDP announcements from the Engine and receives LLDP announcements from other directly connected devices in the network. Send Only — The interface only sends LLDP announcements from the Engine.
Comment (Optional) | A comment for your own reference.

Option | Definition
--- | ---
Advanced tab (All optional settings)
Override Engine's Default Settings | When selected, the default settings of the Security Engine are overridden.
SYN Rate Limits | Default — The interface uses the SYN rate limits defined for the Security Engine on the Advanced Settings branch of the Engine Editor. None — Disables SYN rate limits on the interface. Automatic — This is the recommended mode if you want to override the general SYN rate limits defined on the Advanced Settings branch of the Engine Editor. The Engine calculates the number of allowed SYN packets per second and the burst size (the number of allowed SYNs before the Security Engine starts limiting the SYN rate) based on the Engine’s capacity and memory size. Custom — Enter the values for Allowed SYNs per Second and Burst Size.
Allowed SYNs per Second | Defines the number of allowed SYN packets per second.
Burst Size | The number of allowed SYNs before the Engine starts limiting the SYN rate. We recommend that you set the burst size to be at least one tenth of the Allowed SYNs per Second value. If the burst size is too small, SYN rate limits do not work. For example, if the value for Allowed SYNs per Second is 10000, set the value for Burst Size to at least 1000.
Enable Log Compression | By default, each generated Antispoofing and Discard log entry is logged separately and displayed as a separate entry in the Logs view. Log Compression settings allow you to define the maximum number of separately logged entries. When the defined limit is reached, a single antispoofing log entry or Discard log entry is logged. The single entry contains information about the total number of the generated Antispoofing log entries or Discard log entries. After this log entry, the logging returns to normal and all generated entries are once more logged and displayed separately. Log Compression is useful when the routing configuration generates a large volume of antispoofing logs or the number of Discard logs becomes high. For each event type, Antispoofing or Discard, you can define: Log Rate (Entries/s) — The maximum number of entries per second. The default value for antispoofing entries is 100 entries/s. By default, Discard log entries are not compressed. Burst Size (Entries) — The maximum number of matching entries in a single burst. The default value for antispoofing entries is 1000 entries. By default, Discard log entries are not compressed.
Set to Default | Returns all changes to the log compression settings to the default settings.

## Layer 2 Physical Interface Properties dialog box (Master Engine and Virtual Engine)

Use this dialog box to define the Layer 2 Physical Interface properties for a Master Engine in the Engine/VPN role or a Virtual Engine.

Note: The available options can vary depending on the type of Engine.

Option | Definition
--- | ---
General tab
Interface ID | The Interface ID automatically maps to a physical network port of the same number during the initial configuration of the Engine. The mapping can be changed as necessary through command-line tools. Note: For Master Engines, changes to the interface mapping do not affect the Interface IDs that are defined for Virtual Engines in Virtual Resource elements.
Type | Capture Interface — Network traffic is monitored only. Traffic cannot be blocked. A connection can be terminated by sending a TCP Reset response. Inline IPS Interface — The interface is directly on the traffic path so that traffic passes through the interface to reach its destination. Inline Layer 2 Engine Interface — The interface is directly on the traffic path so that traffic passes through the interface to reach its destination.
Failure Mode | (When Type is Inline IPS Interface) Select how traffic to the Inline IPS Interface is handled if the Security Engine goes offline. Bypass — traffic is allowed through the Inline Interface without inspection. Normal — traffic is not allowed through the Inline Interface. CAUTION: Using bypass mode requires a fail-open network interface card. If the ports that represent the interfaces cannot fail open, policy installation fails on the Security Engine. Bypass mode is not compatible with VLAN retagging. In network environments where VLAN retagging is used, normal mode is automatically enforced.
Bypass unspecified VLANs | When selected, traffic from VLANs that are not allocated to any Virtual Engine is bypassed without inspection. Deselect this option to make the Master Engine block traffic from VLANs that are not allocated to any Virtual Engine. We recommend that you keep this option selected if you do not have a specific reason to deselect it.
Inspect QinQ | Select this option to make the engine inspect double-tagged VLAN traffic as defined in IEEE 802.1Q. We recommend that you keep this option selected if you do not have a specific reason to deselect it.
Virtual Resource | The Virtual Resource associated with the interface. Select the same Virtual Resource in the properties of the Virtual Engine to add the Virtual Engine to the Master Engine. If the interface is to be used for the Master Engine system communications, select None. For Master Engines that host Virtual Engines, you can select Multiple Virtual Resources to allow several Virtual Engines to share a single physical interface. To add multiple Virtual Resources for Virtual IPS engines or Virtual Layer 2 Engines, add VLAN Interfaces to the Physical Interface, then select a Virtual Resource in the properties of each VLAN Interface.
MTU (Optional) | The maximum transmission unit (MTU) size on the connected link. Either enter a value between 400–65535 or select a common MTU value from the list. If the interface is a Physical Interface, the same MTU is automatically applied to any VLANs created under it. The default value (also the maximum standard MTU in Ethernet) is 1500. Do not set a value larger than the standard MTU, unless you know that all devices along the communication path support it. To set the MTU for a Virtual Engine, you must configure the MTU for the interface on the Master Engine that hosts the Virtual Engine, then refresh the policy on the Master Engine and the Virtual Engine.
Comment (Optional) | A comment for your own reference.

Option | Definition
--- | ---
Advanced tab (All optional settings)
Override Engine's Default Settings | When selected, the default settings of the Security Engine are overridden.
SYN Rate Limits | Default — The interface uses the SYN rate limits defined for the Security Engine on the Advanced Settings branch of the Engine Editor. None — Disables SYN rate limits on the interface. Automatic — This is the recommended mode if you want to override the general SYN rate limits defined on the Advanced Settings branch of the Engine Editor. The Engine calculates the number of allowed SYN packets per second and the burst size (the number of allowed SYNs before the Security Engine starts limiting the SYN rate) based on the Engine’s capacity and memory size. Custom — Enter the values for Allowed SYNs per Second and Burst Size.
Allowed SYNs per Second | Defines the number of allowed SYN packets per second.
Burst Size | The number of allowed SYNs before the Engine starts limiting the SYN rate. We recommend that you set the burst size to be at least one tenth of the Allowed SYNs per Second value. If the burst size is too small, SYN rate limits do not work. For example, if the value for Allowed SYNs per Second is 10000, set the value for Burst Size to at least 1000.
Enable Log Compression | By default, each generated Antispoofing and Discard log entry is logged separately and displayed as a separate entry in the Logs view. Log Compression settings allow you to define the maximum number of separately logged entries. When the defined limit is reached, a single antispoofing log entry or Discard log entry is logged. The single entry contains information about the total number of the generated Antispoofing log entries or Discard log entries. After this log entry, the logging returns to normal and all generated entries are once more logged and displayed separately. Log Compression is useful when the routing configuration generates a large volume of antispoofing logs or the number of Discard logs becomes high. For each event type, Antispoofing or Discard, you can define: Log Rate (Entries/s) — The maximum number of entries per second. The default value for antispoofing entries is 100 entries/s. By default, Discard log entries are not compressed. Burst Size (Entries) — The maximum number of matching entries in a single burst. The default value for antispoofing entries is 1000 entries. By default, Discard log entries are not compressed.
Set to Default | Returns all changes to the log compression settings to the default settings.

## Physical Interface Properties dialog box (IPS engine)

Use this dialog box to define the Physical Interface properties for a Single IPS engine, IPS Cluster, Virtual IPS engine, or Master Engine in the IPS role.

Note: The available options can vary depending on the type of IPS engine.

Option | Definition
--- | ---
General tab
Interface ID | The Interface ID automatically maps to a physical network port of the same number during the initial configuration of the Engine. The mapping can be changed as necessary through command-line tools. Note: For Master Engines, changes to the interface mapping do not affect the Interface IDs that are defined for Virtual Engines in Virtual Resource elements.
Type | Normal Interface — Corresponds to a single network interface on the engine. Not supported on Virtual IPS engines. Capture Interface — Network traffic is monitored only. Traffic cannot be blocked. Inline Interface — The interface is directly on the traffic path so that traffic must always pass through the engine to reach its destination. Only traffic that attempts to pass through Inline Interfaces can be actively filtered.
Zone (Optional) | Select the network zone to which the interface belongs. Click Select to select an element, or click New to create an element.
MTU (Optional) | The maximum transmission unit (MTU) size on the connected link. Either enter a value between 400–65535 or select a common MTU value from the list. If the interface is a Physical Interface, the same MTU is automatically applied to any VLANs created under it. The default value (also the maximum standard MTU in Ethernet) is 1500. Do not set a value larger than the standard MTU, unless you know that all devices along the communication path support it. To set the MTU for a Virtual Engine, you must configure the MTU for the interface on the Master Engine that hosts the Virtual Engine, then refresh the policy on the Master Engine and the Virtual Engine.
Comment (Optional) | A comment for your own reference.

Option | Definition
--- | ---
Inline Interface Settings or Capture Interface Settings section
Reset Interface | (When Type is Capture Interface) Select the Reset Interface to specify the interface through which TCP connection resets are sent when Reset responses are used in your policy.
Logical Interface | Specifies the Logical Interface. You cannot use the same Logical Interface element for both Inline and Capture Interfaces on the same Virtual Engine.
Failure Mode | (When Type is Inline Interface) Select how traffic to the Inline Interface is handled if the engine goes offline. Bypass — traffic is allowed through the Inline Interface without inspection. Normal — traffic is not allowed through the Inline Interface. Note: If there are VLAN Interfaces under the Inline Interface, you must select Bypass. Note: For Virtual Engines, this option is set on the Master Engine. CAUTION: Using bypass mode requires a fail-open network interface card. If the ports that represent the interfaces cannot fail open, policy installation fails on the Security Engine. Bypass mode is not compatible with VLAN retagging. In network environments where VLAN retagging is used, normal mode is automatically enforced.
Inspect unspecified VLANs | (When Type is Capture Interface or Inline Interface) Select this option to make the engine inspect traffic from VLANs that are not included in the engine’s interface configuration. We recommend that you keep this option selected if you do not have a specific reason to deselect it.
Inspect QinQ | Select this option to make the engine inspect double-tagged VLAN traffic as defined in IEEE 802.1Q. We recommend that you keep this option selected if you do not have a specific reason to deselect it.
Bypass unspecified VLANs (Master Engines only) | (When Type is Inline Interface) When this option is selected, traffic from VLANs that are not allocated to any Virtual Engine is bypassed without inspection. Deselect this option to make the Master Engine block traffic from VLANs that are not allocated to any Virtual Engine. We recommend that you keep this option selected if you do not have a specific reason to deselect it.

Option | Definition
--- | ---
Second Interface section (When Type is Inline Interface)
ID | Select a Second Interface ID. The Interface ID is mapped to a physical network port of the same number during the initial configuration of the engine.
Zone (Optional) | Select the network zone to which the interface belongs. Click Select to select an element, or click New to create an element.
Second Interface ID (Master Engines only) | Select a Second Interface ID. The Interface ID is mapped to a physical network port of the same number during the initial configuration of the engine.

Option | Definition
--- | ---
QoS Mode (Optional) | Select the QoS mode to apply to the link on this interface. You can select from one of the following options: No QoS: When selected, no QoS mode is enabled. QoS Statistics Only: It allows the collection of QoS Class-based counters without activating any other QoS feature. DSCP Handling and Throttling: When selected, no queues and no throttling of all traffic. Only the connections that are tagged with QoS Class are treated as per the action that is defined in the QoS policy. Full QoS: It throttles all traffic to the Interface Throughput Limit that is set in the interface properties Note: If Full QoS or DSCP Handling and Throttling is selected, a QoS policy must also be selected. If Full QoS is selected, the throughput must also be defined. If the interface is a Physical Interface, the same QoS mode is automatically applied to any VLANs created under it.
QoS Policy | (When QoS Mode is Full QoS or DSCP Handling and Throttling) The QoS policy for the link on this interface. If the interface is a Physical Interface, the same QoS policy is automatically selected for any VLANs created under it. Note: If a Virtual Resource has a throughput limit defined, the interfaces on the Virtual Engine that use a QoS policy all use the same policy. The policy used in the first interface is used for all the interfaces.
Interface Throughput Limit | (When QoS Mode is Full QoS) Enter the throughput for the link on this interface as megabits per second. If the interface is a Physical Interface, the same throughput is automatically applied to any VLANs created under it. The throughput is for uplink speed (outgoing traffic) and typically must correspond to the speed of an Internet link (such as an ADSL line), or the combined speeds of several such links when connected to a single interface. CAUTION: Make sure that you set the interface speed correctly. When the bandwidth is set, the Engine always scales the total amount of traffic on this interface to the bandwidth you defined. This scaling happens even if there are no bandwidth limits or guarantees defined for any traffic. CAUTION: The throughput for a Physical Interface for a Virtual Engine must not be higher than the throughput for the Master Engine interface that hosts the Virtual Engine. Contact the administrator of the Master Engine before changing this setting.

Option | Definition
--- | ---
Virtual Resource section (Master Engines only)
Virtual Resource | The Virtual Resource associated with the interface. Select the same Virtual Resource in the properties of the Virtual Engine to add the Virtual Engine to the Master Engine. If the interface is to be used for the Master Engine system communications, select None. For Master Engines that host Virtual Engines, you can select Multiple Virtual Resources to allow several Virtual Engines to share a single physical interface. To add multiple Virtual Resources for Virtual IPS engines or Virtual Layer 2 Engines, add VLAN Interfaces to the Physical Interface, then select a Virtual Resource in the properties of each VLAN Interface.
Allow VLAN Definition in Virtual Engine | (When the Virtual Resource option is a single Virtual Resource) When selected, you can add VLAN Interfaces to the automatically created physical interfaces in the Virtual Security Engines that are associated with this interface.
Virtual Engine Interface ID | (When the Virtual Resource option is a single Virtual Resource) Specifies the Interface ID of the Physical Interface in the Virtual Engine that is associated with this interface.

Option | Definition
--- | ---
Advanced tab (All optional settings)
Override Engine's Default Settings | When selected, the default settings of the Security Engine are overridden.
SYN Rate Limits | Default — The interface uses the SYN rate limits defined for the Security Engine on the Advanced Settings branch of the Engine Editor. None — Disables SYN rate limits on the interface. Automatic — This is the recommended mode if you want to override the general SYN rate limits defined on the Advanced Settings branch of the Engine Editor. The Engine calculates the number of allowed SYN packets per second and the burst size (the number of allowed SYNs before the Security Engine starts limiting the SYN rate) based on the Engine’s capacity and memory size. Custom — Enter the values for Allowed SYNs per Second and Burst Size.
Allowed SYNs per Second | Defines the number of allowed SYN packets per second.
Burst Size | The number of allowed SYNs before the Engine starts limiting the SYN rate. We recommend that you set the burst size to be at least one tenth of the Allowed SYNs per Second value. If the burst size is too small, SYN rate limits do not work. For example, if the value for Allowed SYNs per Second is 10000, set the value for Burst Size to at least 1000.
Enable Log Compression | By default, each generated Antispoofing and Discard log entry is logged separately and displayed as a separate entry in the Logs view. Log Compression settings allow you to define the maximum number of separately logged entries. When the defined limit is reached, a single antispoofing log entry or Discard log entry is logged. The single entry contains information about the total number of the generated Antispoofing log entries or Discard log entries. After this log entry, the logging returns to normal and all generated entries are once more logged and displayed separately. Log Compression is useful when the routing configuration generates a large volume of antispoofing logs or the number of Discard logs becomes high. For each event type, Antispoofing or Discard, you can define: Log Rate (Entries/s) — The maximum number of entries per second. The default value for antispoofing entries is 100 entries/s. By default, Discard log entries are not compressed. Burst Size (Entries) — The maximum number of matching entries in a single burst. The default value for antispoofing entries is 1000 entries. By default, Discard log entries are not compressed.
Set to Default | Returns all changes to the log compression settings to the default settings.

## Physical Interface Properties dialog box (Layer 2 Engine)

Use this dialog box to define the Physical Interface properties for a Single Layer 2 Engine, Layer 2 Engine Cluster, Virtual Layer 2 Engine, or Master Engine in the Layer 2 Engine role.

Note: The available options can vary depending on the type of Layer 2 Engine.

Option | Definition
--- | ---
General tab
Interface ID | The Interface ID automatically maps to a physical network port of the same number during the initial configuration of the engine. The mapping can be changed as necessary through the engine’s command line interface. Note: Changes to the Master Engine interface mapping do not affect the Interface IDs that are defined for Virtual Engines in Virtual Resource elements.
Type | Normal interface — Corresponds to a single network interface on the Layer 2 Engine. Capture Interface — Traffic is only captured for inspection. Note: Capture Interfaces allow the hosted Virtual Layer 2 Engine to listen to traffic that is not routed through the Master Engine. You can have as many Capture Interfaces as there are available physical ports on the Master Engine. External equipment must be set up to mirror traffic to the Capture Interface. Inline Interface — The interface is directly on the traffic path so that traffic must always pass through the Layer 2 Engine to reach its destination. Only traffic that attempts to pass through Inline Interfaces can be actively filtered. Note: An Inline Interface consists of two different Physical Interfaces on the Master Engine. This way, the hosted Virtual Layer 2 Engine can inspect the traffic coming from one interface and either stop the traffic or send it out through the other interface.
Zone (Optional) | Select the network zone to which the interface belongs. Click Select to select an element, or click New to create an element.
MTU (Optional) | The maximum transmission unit (MTU) size on the connected link. Either enter a value between 400–65535 or select a common MTU value from the list. If the interface is a Physical Interface, the same MTU is automatically applied to any VLANs created under it. The default value (also the maximum standard MTU in Ethernet) is 1500. Do not set a value larger than the standard MTU, unless you know that all devices along the communication path support it. To set the MTU for a Virtual Engine, you must configure the MTU for the interface on the Master Engine that hosts the Virtual Engine, then refresh the policy on the Master Engine and the Virtual Engine.
Comment (Optional) | A comment for your own reference.

Option | Definition
--- | ---
Inline Interface Settings or Capture Interface Settings section
Reset Interface | (When Type is Capture Interface) Select the Reset Interface to specify the interface through which TCP connection resets are sent when Reset responses are used in your policy.
Logical Interface | Specifies the Logical Interface. You cannot use the same Logical Interface element for both Inline and Capture Interfaces on the same Virtual Engine.
Inspect unspecified VLANs | (When Type is Capture Interface or Inline Interface) Deselect this option to make the Security Engine ignore traffic from VLANs that are not included in the Security Engine's interface configuration. We recommend that you keep this option selected if you do not have a specific reason to deselect it.
Inspect QinQ | Select this option to make the engine inspect double-tagged VLAN traffic as defined in IEEE 802.1Q. We recommend that you keep this option selected if you do not have a specific reason to deselect it.
Bypass unspecified VLANs (Master Engines only) | (When Type is Inline Interface) When this option is selected, traffic from VLANs that are not allocated to any Virtual Engine is bypassed without inspection. Deselect this option to make the Master Engine block traffic from VLANs that are not allocated to any Virtual Engine. We recommend that you keep this option selected if you do not have a specific reason to deselect it.

Option | Definition
--- | ---
Second Interface section (Inline Interfaces only)
ID | Select a Second Interface ID. The Interface ID is mapped to a physical network port of the same number during the initial configuration of the engine. Note: Select the Second Interface ID of the Inline Interface in the Virtual Layer 2 Engine that is associated with this interface.
Zone (Optional) | Select the network zone to which the interface belongs. Click Select to select an element, or click New to create an element.
Second Interface ID (Master Engines only) | (When Type is Inline Interface) Select a Second Interface ID. The Interface ID is mapped to a physical network port of the same number during the initial configuration of the engine.

Option | Definition
--- | ---
QoS Mode (Optional) | Select the QoS mode to apply to the link on this interface. You can select from one of the following options: No QoS: When selected, no QoS mode is enabled. QoS Statistics Only: It allows the collection of QoS Class-based counters without activating any other QoS feature. DSCP Handling and Throttling: When selected, no queues and no throttling of all traffic. Only the connections that are tagged with QoS Class are treated as per the action that is defined in the QoS policy. Full QoS: It throttles all traffic to the Interface Throughput Limit that is set in the interface properties Note: If Full QoS or DSCP Handling and Throttling is selected, a QoS policy must also be selected. If Full QoS is selected, the throughput must also be defined. If the interface is a Physical Interface, the same QoS mode is automatically applied to any VLANs created under it.
QoS Policy | (When QoS Mode is Full QoS or DSCP Handling and Throttling) The QoS policy for the link on this interface. If the interface is a Physical Interface, the same QoS policy is automatically selected for any VLANs created under it. Note: If a Virtual Resource has a throughput limit defined, the interfaces on the Virtual Engine that use a QoS policy all use the same policy. The policy used in the first interface is used for all the interfaces.
Interface Throughput Limit | (When QoS Mode is Full QoS) Enter the throughput for the link on this interface as megabits per second. If the interface is a Physical Interface, the same throughput is automatically applied to any VLANs created under it. The throughput is for uplink speed (outgoing traffic) and typically must correspond to the speed of an Internet link (such as an ADSL line), or the combined speeds of several such links when connected to a single interface. CAUTION: Make sure that you set the interface speed correctly. When the bandwidth is set, the Engine always scales the total amount of traffic on this interface to the bandwidth you defined. This scaling happens even if there are no bandwidth limits or guarantees defined for any traffic. CAUTION: The throughput for a Physical Interface for a Virtual Engine must not be higher than the throughput for the Master Engine interface that hosts the Virtual Engine. Contact the administrator of the Master Engine before changing this setting.

Option | Definition
--- | ---
Virtual Resource section (Master Engines only)
Virtual Resource | The Virtual Resource associated with the interface. Select the same Virtual Resource in the properties of the Virtual Engine element to add the Virtual Engine to the Master Engine. Only one Virtual Resource can be selected for each Physical Interface. If you want to add multiple Virtual Resources, add VLAN Interfaces to the Physical Interface, then select the Virtual Resource in the VLAN Interface properties.
Allow VLAN Definition in Virtual Engine | When selected, allows VLAN Interfaces to be added to the automatically created Physical Interfaces in the Virtual Engine that is associated with this interface.
Virtual Engine Interface ID | Specifies the Interface ID of the Physical Interface in the Virtual Engine that is associated with this interface.

Option | Definition
--- | ---
Advanced tab (All optional settings) Note: These options cannot be selected if using Capture Interfaces.
Override Engine's Default Settings | When selected, the default settings of the Security Engine are overridden.
SYN Rate Limits | Default — The interface uses the SYN rate limits defined for the Security Engine on the Advanced Settings branch of the Engine Editor. None — Disables SYN rate limits on the interface. Automatic — This is the recommended mode if you want to override the general SYN rate limits defined on the Advanced Settings branch of the Engine Editor. The Engine calculates the number of allowed SYN packets per second and the burst size (the number of allowed SYNs before the Security Engine starts limiting the SYN rate) based on the Engine’s capacity and memory size. Custom — Enter the values for Allowed SYNs per Second and Burst Size.
Allowed SYNs per Second | Defines the number of allowed SYN packets per second.
Burst Size | The number of allowed SYNs before the Engine starts limiting the SYN rate. We recommend that you set the burst size to be at least one tenth of the Allowed SYNs per Second value. If the burst size is too small, SYN rate limits do not work. For example, if the value for Allowed SYNs per Second is 10000, set the value for Burst Size to at least 1000.
Enable Log Compression | By default, each generated Antispoofing and Discard log entry is logged separately and displayed as a separate entry in the Logs view. Log Compression settings allow you to define the maximum number of separately logged entries. When the defined limit is reached, a single antispoofing log entry or Discard log entry is logged. The single entry contains information about the total number of the generated Antispoofing log entries or Discard log entries. After this log entry, the logging returns to normal and all generated entries are once more logged and displayed separately. Log Compression is useful when the routing configuration generates a large volume of antispoofing logs or the number of Discard logs becomes high. For each event type, Antispoofing or Discard, you can define: Log Rate (Entries/s) — The maximum number of entries per second. The default value for antispoofing entries is 100 entries/s. By default, Discard log entries are not compressed. Burst Size (Entries) — The maximum number of matching entries in a single burst. The default value for antispoofing entries is 1000 entries. By default, Discard log entries are not compressed.
Set to Default | Returns all changes to the log compression settings to the default settings.