> [ bitwise reg 1 = ( reg 1 & 0x0000001f ) ^ 0x000000c0 ] Mask one byte with 31 (lower 5 bits), then XOR with 192 (Upper 2 bits). Why not just set a value of 192? It isn't what was asked for, either. I would hazard a guess, and say that it is broken. It appears as if the EtherType is being re-written to 192; which indicates that it is now an 'old ethernet' length field: definitely broken. I'll have to look into this issue also; though, I can't provide a fix just yet. Hopefully somebody with more experience can chip in here. sunny