topic Re: Invisible NAT rules (twice NAT) added in 8.3 for VPN??!? in Network Security

Invisible NAT rules (twice NAT) added in 8.3 for VPN??!?

golly_wog — Mon, 11 Mar 2019 20:41:18 GMT

People,

Can anyone shed any light on the following for me?

Note If you configure VPN, the client dynamically adds invisible NAT rules to the end of this section. Be sure that you do not configure a twice NAT rule in this section that might match your VPN traffic, instead of matching the invisible rule. If VPN does not work due to NAT failure, consider adding twice NAT rules to section 3 instead.

this is from http://www.cisco.com/en/US/docs/security/asa/asa83/asdm63/configuration_guide/nat_overview.html#wp1118157

Thanks.

Re: Invisible NAT rules (twice NAT) added in 8.3 for VPN??!?

golly_wog — Fri, 03 Jun 2011 09:31:59 GMT

What I'd like to know is, where in the order of NAT rules is this inserted?

From my very limited experience, this did not work with a previously configured (twice/manual), NAT rule, so I can only presume that it's added as a new rule, but if you have any previous rules you need to manually specify these...?

https://supportforums.cisco.com/message/3370889#3370889

Many thanks

Invisible NAT rules (twice NAT) added in 8.3 for VPN??!?

bperkic — Sun, 27 Nov 2011 11:55:15 GMT

Hello,

I would also like to know what does this "invisible NAT rules" part mean, and what does "If you configure VPN" exactly means? What kind of VPN, L2L or RA? How is VPN configuration related to these "invisible NAT rules", i.e. what part of VPN configuration causes these NAT rules to be added and how? Why are these rules "invisible" after all?

Thanks