This could be many reasons, couple of things to check as below :
- Verify the other end has a route outside for the interesting traffic.
- Check that both VPN ACL’s are not mismatched.
- Double check NAT’s to make sure the traffic is not NAT’ing correctly.
- Is what you are trying to ping even responding back? Often what you’re sending traffic to is not able to accept or is not responding to this traffic. I prefer to put a packet capture on the remote end firewall to see if the traffic is coming back into that firewall.
until we know how you configured your running config / nat / acl. its hard to tell.
post configuration of the bot the devices - we asume that tunnel is up and running if so please post also below information.
show crypto ipsec sa (from both the side)
