topic Re: Remote Access on ASA NAT question in Network Security

Remote Access on ASA NAT question

pbwatson4 — Mon, 11 Mar 2019 19:05:38 GMT

I have recently migrated a site from PIX 6.3 using a 3005 for remote access connected to a DMZ interface. The 3005 would assign a IP pool per group and on the PIX this IP range was NATed to the inside interface. The inside interface could reach all the networks required both local and remote as it is seen from the PIX inside interface. The site is now upgraded to ASA 8.2 and the remote access functions are to moved to the ASA. I understand setting up the VPN groups fine but am having issues with getting the NAT to work. I want to replicate the same setup I had with the remote access pools being NATed to the inside interface address. Since these pools originate on the PIX and not a secondary device how does NAT function?

Thanks for any input.

Re: Remote Access on ASA NAT question

Federico Coto Fajardo — Fri, 05 Nov 2010 20:01:29 GMT

Hi,

There are not any major changes to NAT from PIX 6.3 to ASA 8.2

NAT changes completely on ASA 8.3

Could you post a simple drawing on what you're doing so we can help you out?

Federico.

Re: Remote Access on ASA NAT question

pbwatson4 — Sun, 07 Nov 2010 19:29:28 GMT

I understand that NAT is basically the same. The question I have is that as I am moving from using an external device for my remote access to using the ASA itself how does the ASA see the traffic originated by the remote access user. Whereas I now have NAT setup on the DMZ interface to NAT the remote user to the inside interface address when accessing resources on the inside network for a ASA remote access user where is the traffic seen as originating from?

Re: Remote Access on ASA NAT question

Federico Coto Fajardo — Sun, 07 Nov 2010 19:38:59 GMT

The VPN clients get NATed to the inside IP of the ASA?

You can do that....

nat (outside) 1 VPN_Pool outside

global (inside) 1 interface

When the VPN clients connect to the outside interface of the ASA, the ASA will accept the encrypted traffic, will decrypted and will NAT that traffic to the inside IP of the ASA (PAT), to reach the internal network.

NAT is not needed for the VPN to work, but you can configure it like that.

Beware that if you configure NAT on the outside interface, you might have to configure NAT for all incoming traffic as well.

Federico.