Unless you are specifically hiring for low-level network performance tuning (which is not how 99% of Googlers are hired), this still seems like a trivia question that's only marginally related to a person's C(++) competency. My impression is that Google discouraged asking such questions.
I don't code to in C++ anymore. Did a long time ago. I'm looking for careful programmers around security and API design. This is nothing to do with performance tuning. It's to do with security.
Source: worked at Google.