An IP address is normally specified in 32-bit dotted-decimal format:

    xxx.xxx.xxx.xxx

where each xxx is a decimal number from 0 to 255.

However, users have reported that specifying a number with a leading '0' causes the number to be treated as octal rather than decimal.

In other words,

10 is the number ten, specified in decimal.
010 is the number eight, specified in octal.