MTUs Jumbo Frames (Ethernet frames 9000 bytes of payload)

i was reading this article about MTUs Jumbo Frames on ethernet -
http://www.pc-freak.net/blog/tag/mtus/

i greped my Ethernet controller here

Code:

$ lspci | grep [Ee]ther
04:00.0 Ethernet controller: Intel Corporation 82573L Gigabit Ethernet Controller (rev 01)

this is more an educational question. if i set this jumbo value for my ethernet will there be awful packet fragmentation once it travels on to the internet, or will it just be used locally on ethernet, and the internet tcp/ip will work as normal?

sorry if it's a silly question, i promised to spend a bit of time relearning linux. so with time my questions hopefully will have a little more understanding of the subject.