Your question is Networking and Security Troubleshooting. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Walk me through how you would troubleshoot a networking and security issue involving ARP, TCP handshakes, NAT/PAT, SSL handshakes, IPsec, OSPF states, BGP path selection, and TCP header flags/options.