Given that a Cisco switch can be replaced with some other company's switch(at least in theory, idk), without weird unknown cases interfering, why would this be a problem ?
replyNot that straightforward. Similar to CPUs and other HW, there are errata and interop quirks between devices.
replyThere are also tight time budgets (basically SLAs) that must be met along with memory considerations (both in SW and on the NPU/HBM), not to mention how the device needs to respond to load and various failure scenarios.
there is software to simulate any arbitrarily complex network: GNS3, eve-ng, Cisco Modeling labs, etc
replyI'm talking about heterogenous legacy hardware that isn't owned by Cisco, not complex topologies.
replyCisco doesn't talk to devices, Cisco talks protocols, most of them are documented in specs and they are often vendor neutral.
replyif any hardware does not confirm to specs, thats on them and its actually a reason to pull out and replace legacy hw