Unable to ping public ip from outside

[rituporna111]

Hi All,

Our ISP had done the mapping for our private IP to their public ip on their end.

When I configured this private IP for example 10.10.10.10 in a laptop and connected that to the internet connection then the public IP for example 30.30.30.30 is reachable from outside.

But when I configured the same private ip that is 10.10.10.10 in a cisco router and connected that to the internet then this 30.30.30.30 public ip not reachable from outside.

Can you please tell me what configuration need to be done at router end to get this public ip reachable from outside.

Regards,

Rituporna Sarma

[Pawan Raut]

As ISP doing NAT so you don't need NAT related config on your router. When you connect your laptop and assigned IP 10.10.10.10 then you  would also configured some default-gateway on your laptop similarly you need to have default route on your router having next hop is ISP router.

ip route 0.0.0.0 0.0.0.0 <ISP end IP>

[rituporna111]

Hi Pawan,

This default route is already configured.

Actually I had configured IP sla for 2 ISPs.This 10.10.10.10 link is as secondary link and currently other link is using for internet.

This secondary link that is 10.10.10.10 link is also working fine to access internet if the primary link fails.

But the issue is with the public ip accessibility from outside.

Do I need to shut this primary link so that this 10.10.10.10 link is use as primary link to check the public ip accessibility?  

Or do I need to put access-list deny for the 30.30.30.30 public ip ?

Regards,

Rituporna Sarma