Cisco IPS-4255-K9 Installation Guide - Page 32
Inline Interface Pair Mode
UPC - 746320951096
View all Cisco IPS-4255-K9 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 32 highlights
How the Sensor Functions Chapter 1 Introducing the Sensor For More Information • For more information on configuring SPAN/monitor on switches, refer to the following sections in Catalyst 6500 Series Software Configuration Guide, 8.7: - Configuring SPAN, RSPAN and the Mini Protocol Analyzer - Configuring SPAN on the Switch - Configuring Ethernet VLAN Trunks - Defining the Allowed VLANs on a Trunk • For more information on promiscuous mode, see Promiscuous Mode, page 1-12. Inline Interface Pair Mode Operating in inline interface pair mode puts the IPS directly into the traffic flow and affects packet-forwarding rates making them slower by adding latency. This allows the sensor to stop attacks by dropping malicious traffic before it reaches the intended target, thus providing a protective service. Not only is the inline device processing information on Layers 3 and 4, but it is also analyzing the contents and payload of the packets for more sophisticated embedded attacks (Layers 3 to 7). This deeper analysis lets the system identify and stop and/or block attacks that would normally pass through a traditional firewall device. In inline interface pair mode, a packet comes in through the first interface of the pair on the sensor and out the second interface of the pair. The packet is sent to the second interface of the pair unless that packet is being denied or modified by a signature. Note You can configure the AIM IPS, AIP SSM, and NME IPS to operate inline even though these modules have only one sensing interface. Note If the paired interfaces are connected to the same switch, you should configure them on the switch as access ports with different access VLANs for the two ports. Otherwise, traffic does not flow through the inline interface. Figure 1-3 illustrates inline interface pair mode. Figure 1-3 Inline Interface Pair Mode Traffic passes through interface pair 253444 Router Sensor VLAN A Switch Host For More Information For a list of restrictions pertaining to IPS sensor interfaces, see Interface Restrictions, page 1-10. 1-14 Cisco Intrusion Prevention System Appliance and Module Installation Guide for IPS 7.0 OL-18504-01