Configuration Register instructions
The Configuration Register is a 16 bit field that is converted into a hexadecimal value for convenience. As you know each hexadecimal character represents 4 bits. Hexadecimal numbers go from 0 to F and represent decimal numbers from 0 to 15. Hexadecimal numbers generally are preceded by a 0x to clue us in on the fact that we are looking at a hexadecimal number. By default a Cisco router has a Configuration Register setting of 0×0101 so the actual 16 bits would look like 0000000100000001 so now you see that finally there is a use for the hexadecimal numbering system! The bits in the Configuration Register are numbered 0 to 15 and you start from the far right: 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 So for every 4 bits we translate that into hex, observe the following typical Configuration Register: 2 1 0 2 0 ...