"It's probably a network issue" is the phrase that ends more productive debugging sessions than it should, usually because nobody has a systematic way to actually confirm or rule that out, so it becomes a shrug instead of a diagnosis. Here's the checklist I actually run through, roughly in order, when something's acting weird and the network is a suspect. Confirm it's actually the network before you go further. Before diving into network-specific tools, rule out the obvious alternative: is ...