Hellow, i'm just tring to understand how can i get information out of header of mpkt...so made few changes in eg. code of chapter 5 (which counts the mpkt's)...but not able to understand where m i going wrong...actually i'm not getting expected results.. changes which i made...... 1... added a new structure in buffer.h file typedef struct { unsigned int e_dst_hi32; unsigned int e_dst_lo16 : 16, e_src_hi16 : 16; unsigned int e_src_lo32; } ethernetHeader_t; 2... declared a pointer to this new type and it points to the buffer_handle (adress returned by a function where mpkt. is stored by RFIFO) 3... just checking whether lower 16 bits of dest mac is 0xffff or not...in a if-else block ,,,,,inside while function of main() 4....i have edited the stream, from ix simulator to have mac address as 0xffffffffffff the if block which i added in the main in receive.c file ... if( headerData.e_dst_lo16 == 0xFFFF ) scratch_incr(cntr, no_signal); else scratch_incr(cntr_blocked, no_signal); in this case cntr_blocked is incremented instead of cntr , which is expected. can u expain where m i going wrong... regards, Nitin Makhija