I'm running into an issue where my 6509 with FWSM installed is lets www requests through, but blocks DNS, despite being told to permit both.
Most perversely, it's blocking DNS on my internal networks. I've got the FWSM set up in single context mode, with a 1-port-to-1-vlan relationship for each of the different firewalls, and even the "internal" networks are blocked from each other. So long as either or both the nameserver netblock and the client netblock must transit the FWSM, all DNS traffic fails. (Things work fine whrn the Nameservers are taken off the FWSM and so is the client network. But then what's the point of having an FWSM if you circumvent it for everything?) Meanwhile, web access works fine in all permutations of different networks being on or off the FWSM.
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...