Thank you for asking this question. You must have the the ip firewall enabled, as well as policy-classes created, and access-control lists (ACLs) to match traffic to be NAT'ed. Additional information about the firewall and setting up NAT can be found in the IPv4 Firewall Protection in AOS, Configuring T1 Internet Access in AOS, and the video Configuring Internet Access (Many to one NAT) with the Firewall Wizard in AOS.
Here is an example NAT configuration:
interface eth 0/1
ip address 192.168.1.1 255.255.255.0
interface ppp 1
ip address 188.8.131.52 255.255.255.252
cross-connect 1 t1 1/1 1 ppp 1
ip access-list standard wizard-ics
remark Internet Connection Sharing
ip policy-class Private
nat source list wizard-ics interface ppp 1 overload
ip policy-class Public
! Implicit discard
Please review the documents above, and let me know if you have any question.
I have marked this post as "assumed answered," but do not hesitate to reply to this thread if you have further questions on this topic. I will be happy to help.
I went ahead and flagged the "Correct Answer" on this post to make it more visible and help other members of the community find solutions more easily. If you don't feel like the answer I marked was correct, feel free to come back to this post and unmark it and select another in its place with the applicable buttons. If you still need assistance, we would be more than happy to continue working with you on this - just let us know in a reply.