Place the troubleshooting steps in the correct order to diagnose a failed ICMP ping between two hosts across a site-to-site IPsec VPN tunnel.

### The order 1. **Confirm host addresses and default gateways**: an endpoint with incorrect network settings cannot reliably reach its local firewall or return traffic. 2. **Check routes, source NAT, and security policies**: these determine the path, packet addresses, and whether transit traffic is allowed. 3. **Check ping permissions and IKE/IPsec tunnel status**: verify interface access when pinging the firewall and verify VPN establishment for inter-site traffic. 4. **Inspect the traffic log**: use the recorded addresses, application, action, and rule to see how the firewall handled the session. ### Terms - **NAT**: Network Address Translation, which changes packet addresses. - **IKE**: Internet Key Exchange, used to negotiate VPN settings. - **IPsec**: Internet Protocol Security, used to protect traffic. ### Remember Start with endpoint settings, then trace the forwarding path and firewall decision.