Routing issue with Cisco ISR4451-X

[AWRIGHT337]

Ok, I have a weird issue going on and it frankly has my coworkers and I stumped.  From any host computer on our network we can ping a specific IP address that is outside our network but when we try to do it from our router, it doesn't work.  This is weird because the router is what directs the traffic from the hosts to outside networks so it has to be able to communicate with this outside IP address.  

Any suggestions?

[Richard Burts]

My suggestion is to give us some detail to work with. We have no idea of how the router is configured, of what its routing table looks like, no idea of what security policies are implemented, no idea of what kind of host is involved, what the addressing of any host is, what routing information might exist on the host.

Give us some detail to work with and we might find an explanation.

[Jon Marshall]

Just to add to Rick's answer which I agree with. 

Routing is based on destination IPs so if your router is not doing NAT then it may be your LAN subnet is being advertised out but the WAN subnet your router uses is not so when you ping from the router there are no return routes for that subnet. 

Try doing the ping on the router but use the LAN interface as the source IP and see if the ping works. 

Jon

[paul driver]

Hello
Just to let you know if you are performing NAT, then this could be the reason, as by default NAT isn’t applicable to traffic initiated from the rtr itself only from behind the rtr performing NAT

Edited - @Jon Marshall apologies Jon didn’t release you had post regards NAT

[Jon Marshall]

Paul

No worries, my post was about not doing NAT so your point applies as well. 

Jon