//\r
// Multicast option, if it is a request, the value must be a zero\r
// length string, otherwise, it is formated like "204.0.0.1,1857,1\0"\r
//\r
// Multicast option, if it is a request, the value must be a zero\r
// length string, otherwise, it is formated like "204.0.0.1,1857,1\0"\r