def ip4_subnet_range_check(strg, loc, toks):
    """
    s = the original string being parsed
    loc = the location of the matching substring
    toks = a list of the matched tokens, packaged as a ParseResults object
    """
    value = int(toks[0])
    if value < 1 or value > 31:
        print('IPv4 subnet is out of range: %d' % value)
        print('strg: %s' % strg)
        print('loc: %s' % loc)
    return None
