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by noncoml 8 days ago
> but rather, was refusing to accept that the scenario they're talking through with you would ever involve an effectively deployed cut-through switch (since that's basically never).

Nope, the argument was exactly if a cut-through switch exists or ever existed

Edit: Actually the conversation came back to me:

He asked me about the frame format. Once I drew that on the board, he asked why is the DST before the SRC. My answer was in order for the switch to start doing the lookups ASAP and that's when I mentioned that a cut-through switch can switch the packet before it even finishes receiving it.

After that we spend the rest of the interview time arguing if cut-through switches actually exist or not. Both he and I having too big of an ego to let it go..

1 comments

So he didn't want to google it?
If you Google it, you find many copies of theory, but not a single reference to a cut-through switch ever existing in real life.
From Arista documentation:

“Arista data planes support these packet forwarding modes: Store and forward: the switch accumulates entire packets before forwarding them. Cut through: the switch begins forwarding frames before their reception is complete.”

You sure? There is one described here: https://en.wikipedia.org/wiki/Cut-through_switching (Kalpana switch from the early 90's)
I see you've never had a run-in with a blowhard in a position of power. Lucky.
I've had it happen in an interview, many years ago. I told him we'd have to agree to disagree. After I was hired, he admitted he looked it up and I was correct (some weird SQL question he asked.)
After I was hired, he admitted he looked it up and I was correct

The best possible outcome.

“So he didn't want to google it?”

No, he didn’t want interrupt the interview to start checking out phones.

“I told him we'd have to agree to disagree.”

That’s where I went wrong. But I like to think learned my lesson.