Exercise 3: Why Ticket 3 Looked Like Chapter 8's Ticket, and What Ruled That Out — Possible Solution ==================================================================== WHY IT LOOKED LIKE THE SAME PROBLEM AT FIRST ------------------------------ Per this chapter, "the first instinct is to assume this is Chapter 8's own certificate-trust issue again - a script failing where a browser succeeds." Both tickets share the exact same surface symptom shape: an automated script fails against an API that a browser, tested manually from the same network, reaches without any problem. THE SPECIFIC EVIDENCE THAT RULED IT OUT ------------------------------ Per this chapter, checking the actual failure directly showed two things Chapter 8's certificate-trust scenario would not produce: "curl -v shows the TLS handshake completing cleanly every time," and the failure itself was "a genuine 504 Gateway Timeout - a real HTTP response, which per Chapter 9 already proves DNS, network reachability, the port, and TLS all worked on that specific attempt." A certificate-trust failure would have shown a TLS handshake error, not a completed handshake followed by an HTTP-level timeout response - so the actual evidence didn't match the assumed cause at all. WHAT THE REAL CAUSE TURNED OUT TO BE ------------------------------ Per this chapter, a traceroute run from the actual batch server (not an ordinary workstation) revealed the script's traffic took a genuinely different path - through a secondary backup VPN tunnel with real latency and packet loss - explaining the intermittent 504s as a routing/timing issue specific to where the script's traffic originates, not a certificate or trust problem at all. WHY THIS WORKS AS AN ANSWER ------------------------------ It explains why the symptom pattern superficially resembled Chapter 8's own ticket, names the specific evidence (a clean TLS handshake and a real HTTP 504 response) that contradicted the certificate-trust explanation, and correctly checked rather than assumed - the same "check, don't guess" discipline the chapter's own tip-box names explicitly.