def sort_ipv4(ips):
    """
    Sort a list of ipv4 addresses in ascending order
    """
    for i in range(len(ips)):
        ips[i] = "%3s.%3s.%3s.%3s" % tuple(ips[i].split("."))
    ips.sort()
    for i in range(len(ips)):
        ips[i] = ips[i].replace(" ", "")   
        
    return ips