From what I could find online, Loggenberg is most frequent in South Africa.
MY NAME IS LOGGENBERG..BO OF 17 YEARS OLD..GR12 ...MY SURNAME........NOT POPULAR...SO IM CURIOUS TO KNOW WHERE DID IT ORIGINATE?
I know you want to know your name origin, but deliberately putting your full real name, with age and school, on this and any worldwide site is never ever a good idea. Yes, I know our names are out there, but....
Post your last name only, remove your personal information.
If you really want to know ... You should ask your parents. Chances are that one of them, or a relative, did some genealogy work on your family and can give you more information than strangers could.
see //references-definitions.blurtit.com/109717/my-surname-is-loggenberg-where-does-it-come-from
there are some answers there.