Im not sure where the line is between teasing and bullying?
I was teased for living in an Aboriginal community in primary school and my first year of high school. My parents really instilled in me how sad those kids were and how they learnt that attitude off their parents. They basically said to stand up for what's right and/or ignore them. That worked well for me.
My sister had the same problems and after trying for a length of time to ignore it etc with no success, mum and another parent pulled her and her friend out of school and homeschooled them for the rest of the year til it died down a bit and they got a different teacher.
Im not sure I'd call my experience 'bullying' though as I was very popular otherwise.
ive taught my kids the same thing. I don't step in unless it gets too big for them to handle themselves as I believe it's important for them to have the tools to deal with it on their own if they can.