The ASA FirePOWER module supplies next-generation firewall services, including Next-Generation Intrusion Prevention System (NGIPS), Application Visibility and Control (AVC), URL filtering, and Advanced Malware Protection (AMP).
The ASA FirePOWER module runs a separate application from the ASA. The module can be a hardware module (on the ASA 5585-X only) or a software module (all other models).
For ASA model software and hardware compatibility with the ASA FirePOWER module. The ASA 5506-X and 5512-X do not support the FirePOWER module in 9.10 and later.
Traffic flow through ASA FirePOWER Module
You can configure your ASA FirePOWER module using one of the following deployment models:
You can configure your ASA FirePOWER module in either an inline or a monitor-only deployment. You cannot configure both inline tap monitor-only mode and normal inline mode at the same time on the ASA. Only one type of security policy is allowed. In multiple context mode, you cannot configure inline tap monitor-only mode for some contexts, and regular inline mode for others.
In inline mode, traffic goes through the firewall checks before being forwarded to the ASA FirePOWER module. When you identify traffic for ASA FirePOWER inspection on the ASA, traffic flows through the ASA and the module as follows:
2. Incoming VPN traffic is decrypted.
3. Firewall policies are applied.
4. Traffic is sent to the ASA FirePOWER module.
5. The ASA FirePOWER module applies its security policy to the traffic, and takes appropriate actions.
6. Valid traffic is sent back to the ASA; the ASA FirePOWER module might block some traffic according to its security policy, and that traffic is not passed on.
7. Outgoing VPN traffic is encrypted.
Note: If you have a connection between hosts on two ASA interfaces, and the ASA FirePOWER service policy is only configured for one of the interfaces, then all traffic between these hosts is sent to the ASA FirePOWER module, including traffic originating on the non-ASA FirePOWER interface (because the feature is bidirectional).

Figure 1 Inline Traffic Flow in the ASA
ASA FirePOWER Inline Tap Monitor-Only Mode
In this mode duplicate stream of traffic send to the ASA FirePOWER module for monitoring purposes only. The module applies the security policy to the traffic and lets you know what it would have done if it were operating in inline mode; for example, traffic might be marked “would have dropped” in events. You can use this information for traffic analysis and to help you decide if inline mode is desirable.

Figure 2 Inline Tap Monitor-Only Mode
ASA FirePOWER Passive Monitor-Only Traffic Forwarding Mode
In this mode ASA FirePOWER module work in Intrusion Detection System (IDS), where there is no impact on the traffic , you can configure a traffic forwarding interface. A traffic forwarding interface sends all received traffic directly to the ASA FirePOWER module without any ASA processing.
The module applies the security policy to the traffic and lets you know what it would have done if it were operating in inline mode; for example, traffic might be marked “would have dropped” in events. You can use this information for traffic analysis and to help you decide if inline mode is desirable.
Traffic in this setup is never forwarded: neither the module nor the ASA sends the traffic on to its ultimate destination. You must operate the ASA in single context and transparent modes to use this configuration.
The following figure shows an interface configured for traffic-forwarding. That interface is connected to a switch SPAN port so the ASA FirePOWER module can inspect all of the network traffic. Another interface sends traffic normally through the firewall.

Figure 3 Passive Monitor-Only, Traffic-Forwarding Mode