Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

NAT TCP port forwarding and VPN's


In the past I have had no problems handling static one to one NAT mappings along with IPSEC VPNs. However, in trying to do TCP port mappings, the standard way of delaing with the static mappings is not working, the internal server that has the NAT mapping can no longer communicate out to the Internet. Can anyone tell me what is wrong with the below config that has TCP port mappings?

My first guess is I need to kill the line in 107 denying Dynamic NAT since I want the server to be able to establish outbound connections on any port. But Will it conflict with the static port mappings ?

Here is the NAT portion of the config::

ip nat inside source list 107 interface Ethernet0/0 overload

ip nat inside source static tcp 25 x.x.x.x 25 extendable

ip nat inside source static tcp 3389 x.x.x.x 3389 extendable



access-list 107 remark DENY DYNAMIC NAT FOR VPN

access-list 107 deny ip host any

access-list 107 deny ip

access-list 107 permit ip any

access-list 108 permit ip host


route-map nonat2 permit 10

match ip address 108

set ip next-hop

  • Other Security Subjects

Re: NAT TCP port forwarding and VPN's

You did not mention the version, however, from what I understand from the part of configurations, I guess this is 11.3; You can try with a later version.

This widget could not be displayed.