Currently I have users that connect with the Cisco VPN client to our PIX 515e. Our corporate network is also directly connected to our partners network, sharing common address space. I want to be able allow our VPN users to connect to certain resources on their network. Since they already have routing for our address space, can I allow the VPN to only NAT traffic to certain destination addresses with a local IP address on our network? That way the partner's network does not have to change any routing since they would see the source address as a local IP on our network.
I don't know if I worded this too confusingly, but let me know if I need to provide any more clarification.
yes this should be no problem - you can use policy NAT for that, e.g.
access-list polnat permit ip 10.10.10.0 255.255.255.0 172.16.0.0 255.255.0.0
nat (outside) 1 access-list polnat outside
global (inside) 1 192.168.1.1
where 10.10.10.x is the vpn pool, 172.16.x.x is the partner network, and 192.168.1.1. is the address you want to NAT the clients to (this can also be "interface" if you want to use the Pix's address, or it can be a range of addresses if you want to do NAT instead of PAT).
Note that if you have nat exemption configured (aka "nat 0"), then you have to make sure the traffic to be natted does not match the nat exemption (otherwise the nat exemption takes precedence over the policy nat).
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...