Same-node pod calls work, cross-node calls time out, and small probes pass while real requests hang. Find the break.

Same-node good, cross-node bad is not a random clue, it is nearly a diagnosis. One short decision tree separates overlay reachability, encapsulation blocks, MTU and policy.

Grounded in researched DevOps, SRE and platform engineering interview loops, written to a senior-engineer editorial bar, and never padded to hit a word count.