An IPSec VPN is implemented between Site A and Site B. Some "nat 0" commands are used on Site A PIX to avoid addresses being translated when communicating with site B.
But now there is a problem, there are several public servers which have static NAT entries by "static" command. And it looks like these entry will still be valid even if the "nat 0" is presenting. And thus those inside IPs which have a static NAT, will be translated once it reaches the PIX and can not go via the VPN tunnel.
May someone advise me how to overcome this? Thanks.
Your question really pertains to the nat order of operations. Nat 0 (nat exemption) is first in the order. It preceeds all other including static nat. The servers you mention will absolutely be included in the nat 0 unless they are specifically denied in the nat 0 acl.
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...