You need to perform the failopen function outside the IPS sensor.
Use an external (to the sensor) switch, create two VLANS, connect them together via the sensor (each VALN to sensor connection is a Trunk with one one VLAN in it). Then create a second connection via a patch cable betwen the two VLANS, give it a higher STP metric, enable Spanning tree on these 4 ports. The bypass cable will only run traffic if the sensor stops passing BPDUs.
I understood the STP part but not the connections part. I´m using only 1 interface to do the VLAN PAIR, the retag is being done in an interface.(and 1 interface in the switch). where should I connect the 4 ports.
If you're only using one interface on the sensor, then you only need three switch ports; one trunking both VLANS to the sensor and one port in each VLAN as a regular (non-trunked) access port connected together via a patch cable.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...