unable to ping other LAN with PAT

[tyr668]

hi guys ,

Why am I able to ping all the public IP addresses from both my LANs using PAT? but it failed when I tried pinging from left LAN to right LAN (or vice versa) . However, if I remove all the PAT configuration, then pinging is successful. also , how do i configure the HQ server network with the website to be accessible from internet using DNAT (should be configured by using the next available public IP address range.) instead of SNAT . currently static nat for the web server has been configured. 

[marce1000]

 - Checkout : https://learningnetwork.cisco.com/s/topic/0TO6e000000WEorGAG/packet-tracer

 M.

[tyr668]

hi , can't seem to access that link

[marce1000]

             - Better is to explain what happens then (too) , 

 M.

[MHM Cisco World]

Friend 

PAT is unidirectional NATing 

Static NAT is bidirectional NATing 

So ping from outside to host inside using public ip is never work with PAT.

You need to use 1:1 static NAT

[tyr668]

but both my lans are running on private IPs . it just got PAT on each of the exit router 

[MHM Cisco World]

again the PAT is unidirectional from Inside to Outside 
so 
LAN1-R1(PAT)-WAN-R2(PAT)-LAN2 

when you ping from LAN1 to LAN2 
you need to use private IP of LAN2 in Ping 
you need to sure that LAN1 and LAN2 reachable to each other 

Thanks A Lot
MHM 

[Martin L]

Normally, in real world, communication between HQ and branch offices is done via VPN and/or private tunnels.  ISP will never route Private IP ranges; PAT/NAT is mostly used to reach Internet. So, I am not sure about this assignment.

As per MHM suggestion of 1:1 static NAT, if u add ip nat inside source static 10.19.0.2 200.100.0.30 on Branch router u should be able to ping PC1 to server0. 

and "PAT is unidirectional from Inside to Outside" is just like your home router set up. in case u reaching this site,  you must initiate traffic not the other way around. 

Regards, ML
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