Exercise 1: HTTPS Works But Ping Fails — Why Nothing Is Necessarily Wrong — Possible Solution
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Explanation:

Per the chapter's own opening limitation on ping, "ping confirms
Network-layer reachability, nothing more. A 'yes' from ping doesn't
guarantee the actual service you care about... is reachable at all;
many servers and firewalls block ICMP entirely while the real service
works perfectly fine." This scenario is precisely the mirror image of
that statement: the real service (HTTPS) is confirmed working
directly -- a browser successfully completed the request -- while ping,
which only tests ICMP specifically, fails. These are two genuinely
independent tests of two different things, not two measurements of the
same underlying fact.

Per the chapter's own warn-box, "ICMP is frequently blocked
deliberately by firewalls while the actual service being checked
works completely fine -- a failed ping means 'ICMP didn't get a
reply,' nothing more specific than that." A great many production
servers and their firewalls are deliberately configured to block or
rate-limit ICMP traffic specifically (often as a defensive measure
against certain types of reconnaissance or denial-of-service activity)
while leaving the actual application ports (443 for HTTPS, in this
case) fully open and functioning normally. The server administrator
made a real, deliberate choice about ICMP specifically that has no
bearing on whether HTTPS itself works.

Since the chapter's own compare-table places ping and HTTPS at
different points in the stack -- ping testing only "basic
reachability" at "Network (Layer 3)," while an actual HTTPS request
succeeding demonstrates the full stack (TCP handshake, TLS handshake,
and the application-layer HTTP exchange itself) is already working
correctly -- a failed ping alongside working HTTPS is not a
contradiction at all. It's exactly the outcome expected when ICMP is
blocked but the real service isn't, which is a common and
intentional server configuration, not a fault.

WHY THIS WORKS AS AN ANSWER
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This explains why ping and an actual HTTPS request test genuinely
different things (per the chapter's own compare-table and warn-box),
rather than treating the failed ping as a red flag that needs
resolving despite the working HTTPS request.