Cisco Cisco Firepower Management Center 2000

Version 5.3

Sourcefire 3D System Release Notes

12

Before You Begin: Important Update and Compatibility Notes

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. 

.

Switching and Routing

Managed devices do not perform switching, routing, NAT, VPN, or related 

functions during the update. If you configured your devices to perform only 

switching and routing, network traffic is blocked throughout the update.

Audit Logging During the Update

When updating appliances that have a web interface, after the Sourcefire 3D 

System completes its pre-update tasks and the streamlined update interface 

page appears, login attempts to the appliance are not reflected in the audit log 

until the update process is complete and the appliance reboots.

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, 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.