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New Member

vpn and nat

i have two networks with private ip address scheme and i want to connect them throug IPsec vpn tunnel, so when i will configure ipsec on both the sides do i need to configure nat or it will work without configuring nat.

Cisco Employee

Re: vpn and nat

Generally you make the IPSec packets bypass NAT, so that each IP address appears as its original address on the other LAN. This way your access-list that defines the encrypted traffic will say "FROM private net TO private net", and your NAT access-list will say "DON'T NAT private net TO private net but DO NAT private net TO anything else".

You don't say what your devices are so I can't help you much more. There's a plethora of sample configs for IPSec here though:

New Member

Re: vpn and nat


I have a question concerning " NAT per-destination-VPN":

from a given site (my site), there are many IPSEC VPNs created to other sites via the internet (site-to-site VPNs). I would like to NAT my site ip adresses, only for a given destination site, and no NAT for others. there might be other constraints as to NAT with different IP ranges for different destination VPNs.

How do we do that?

Thanks. Madjid

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