Cisco Cisco Firepower Management Center 4000 Release Notes

Version 5.3.0.5

Sourcefire 3D System Release Notes

4

Before You Begin: Important Update and Compatibility Notes

Traffic Flow and Inspection During the Update

The update process (and any uninstallation of the update) reboots managed 

devices. Depending on how your devices are configured and deployed, the 

following capabilities are affected:

traffic inspection, including application awareness and control, URL filtering, 

Security Intelligence, intrusion detection and prevention, and connection 

logging 

traffic flow, including switching, routing, NAT, VPN, and related functionality

link state

Note that when you update clustered devices, the system performs the update 

one device at a time to avoid traffic interruption.

Traffic Inspection and Link State

In an inline deployment, your managed devices (depending on model) can affect 

traffic flow via application control, user control, URL filtering, Security 

Intelligence, and intrusion prevention, as well as switching, routing, NAT, and 

VPN. In a passive deployment, you can perform intrusion detection and collect 

discovery data without affecting network traffic flow. For more information on 

appliance capabilities, see the Sourcefire 3D System Installation Guide.
The following table provides details on how traffic flow, inspection, and link state 

are affected during the update, depending on your deployment. Note that 

regardless of how you configured any inline sets, switching, routing, NAT, and 

VPN are not performed during the update process. 

.

Network Traffic Interruption

Inline with 

configurable bypass
(Configurable bypass 

option enabled for 

inline sets)

Network traffic is interrupted at two points during the update:
• At the beginning of the update process, traffic is briefly interrupted while 

link goes down and up (flaps) and the network card switches into hardware 

bypass. Traffic is not inspected during hardware bypass.

• After the update finishes, traffic is again briefly interrupted while link flaps 

and the network card switches out of bypass. After the endpoints reconnect 

and reestablish link with the sensor interfaces, traffic is inspected again. 

 The configurable bypass option is not supported on virtual 

devices, Sourcefire Software for X-Series, non-bypass NetMods on 

8000 Series devices, or SFP transceivers on 71xx Family devices.

Inline

Network traffic is blocked throughout the update.

Passive

Network traffic is not interrupted, but also is not inspected during the update.