Can not ping to a dynamic nat ip address

[SubnetWarrior]

Helo experts, 

So this is my topology : 

PC A and PC B   -  dynamic nat     -       Router 1         -       Router 2          -  PC C

10.10.10.2-3     -   50.50.50.2-5  -   200.200.200.1   -     200.200.200.1  -   172.16.10.2

When i ping from pc A to pc C, it succeed and the nat is establish (Router 1 give PC A nat 50.50.50.2)

When i ping from pc B to pc C, it succeed and the nat is establish (Router 1 give PC B nat 50.50.50.3)

But when i ping from PC C to 50.50.50.2 and 50.50.50.3, it failed (destination host unreachable), i check the routing table on router 2, the routing is fine. 

When i change from dynamic nat to static nat  :

10.10.10.2 <-> 50.50.50.2

10.10.10.3 <-> 50.50.50.3

PC C succesfully ping 50.50.50.2 and 50.50.50.3

So it's the normal behaviour that we can not ping the destination which is dynamic nat?

[balaji.bandi]

Technically you should be able to ping the other way around also. but to confirm what is wrong here. we have only limited information about the problem, you need to provide more information 

Like, device model? what is code running? how your NAT configuration configured? nice to have a configuration bit to understand the problem.

[paul driver · Accepted solution]

Hello

You can use reversible nat, this way you should be able to reach the internal natted host from the outside host up until the reversible 1-1 nat translation it creates expires as such the internal host will need to reinitiate the connection where upon both a dynamic and 1-1 nat entry will be created again.

example:
ip nat pool STAN 50.50.50.2 -50.50.50.10  prefix-length 24 
ip nat inside source route-map NAT pool STAN reversible

access-list 1 permit 10.0.0.0 0.0.0.255
route-map NAT 
match ip address 1

[SubnetWarrior]

Wow thx for the answer and solution sir.
I never know about reversible nat until now.