# NAT Extendable on Cisco IOS **URL:** https://forum.networklessons.com/t/nat-extendable-on-cisco-ios/1416 **Category:** Lessons Discussion **Created:** [January 15, 2017, 10:52am UTC](https://forum.networklessons.com/t/nat-extendable-on-cisco-ios/1416 "2017-01-15T10:52:58Z") **Posts on this page:** 1 **Showing post:** 4
### Author: ![ngcoso](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/n/ebca7d/32.png) [@ngcoso](https://forum.networklessons.com/u/ngcoso) #### Post date: [December 31, 2022, 11:27am UTC](https://forum.networklessons.com/t/nat-extendable-on-cisco-ios/1416/4 "2022-12-31T11:27:34Z")
Can you check if my explanation below is correct? After R1 receives a ping packet from S1, R1 does routing first and then NAT. - Routing first: for destination 192.168.13.3, R1 will use the outgoing interface G0/3 - Then NAT: [s=192.168.1.1, d=192.168.13.3] → [s=192.168.12.100, d=192.168.13.3] After ISP2 receives the traffic from R1, ISP2 won’t be able to reply as it doesn’t know how to reach 192.168.12.100 Another question is: Is there a way to make sure that when we ping 192.168.13.3 from S1, the ping will work? If Cisco already implemented the “extendable” keyword, they should have implemented a way to make the ping work too. It doesn’t make much sense to me. --- _[View the full topic](https://forum.networklessons.com/t/nat-extendable-on-cisco-ios/1416)._