Pretty much everyone knows. Most of my friends are furries, and for those that aren't, they know as well. I never went out of my way and said "Hey you know I'm a furry

" I don't keep it a secret, for sure, but I also don't go around bragging about it. I'm proud to be, don't get me wrong, but that's for me to feel and not rub in the face of everyone around me.
I just do as I do and answer honestly when asked. If someone has a problem with it, I let them go about their business and just leave. Luckily, I haven't had anyone flip their shit about it, but I know someone will in the future. Too bad for them I don't really care and I have a perfect motor assembly to help me vacate their vicinity, or in the case of an online incident, a handy little x.
My father knows and respects my interests, my Grandmother couldn't care less and loves me all the same, my siblings all don't see a problem with it, and I still hold a good share of non-furry/non-brony friends (who shall not be named here) and none of them have anything against it.