One that you can drop in like an ethernet bridge - you do not assign ip addresses to either interface (so it doesn't route). Netscreens can do it, as can linux/bsd boxes.
They are handy when you don't want to re ip address your network to deploy a firewall. Imagine a small company with 100 statically ip addressed workstations on a real class C, connected to a cisco router without the IOS firewall package. Rather than upgrade the router to support the IOS firewall package, you may prefer a more fully featured firewall that can be deployed as a bridge. You would simply configure it, and drop it in place between the ethernet interface of the router, and the uplink to the layer 2 environment for the client machines.
Another upside, is you can have a firewall with no ip address assigned to it - you could this make it almost hack proof, as administration could be limited to physical access. Most bridging firewalls support a management ethernet interface however, for usability
Exactly! ;) We have a WAN with several subsidiaries connected to the head office, For security purposes we now want to implement a firewall solution in every subsidiary, and because of the widespread of computer viruses.
Transparent Mode Firewall will be very handy as we do not have to readdress the entire network.
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...