from the documentation
components of the dotted address can be specified in decimal, octal (with a leading 0), or >hexadecimal, with a leading 0X)
this means that
char USER_IP[16] = "192.168.002.025";
implies 192 168 2 (25 Octal == 21) and
char USER_IP2[16] = "192.168.2.25";
implies 192 168 2 25