Not working in IPv6 networks about mmlanscan HOT 2 CLOSED

#include <arpa/inet.h>
#include <resolv.h>

res_state res = malloc(sizeof(struct __res_state));
     
int result = res_ninit(res);
     
if(result == 0){
    // pass
         
    int nscount = 0;
    union res_sockaddr_union u[MAXNS];
    nscount = res_getservers(res, u, MAXNS);
    NSLog(@"nscount = %d", nscount);
    int i;
    for(i = 0; i < nscount; i++){
        if(u[i].sin.sin_family == PF_INET){
            NSLog(@"IPv4");
            char straddr[INET_ADDRSTRLEN];
            inet_ntop(PF_INET, &u[i].sin.sin_addr, straddr, sizeof(straddr));
            NSString *s = [NSString stringWithCString:straddr encoding:NSASCIIStringEncoding];
            NSLog(@"%@", s);
        }
        if(u[i].sin6.sin6_family == PF_INET6){
            NSLog(@"IPv6");
            //struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&u[i].sin6;
            char straddr[INET6_ADDRSTRLEN];
            inet_ntop(PF_INET6, &u[i].sin6.sin6_addr, straddr, sizeof(straddr));
            NSString *s = [NSString stringWithCString:straddr encoding:NSASCIIStringEncoding];
            NSLog(@"%@", s);
        }
    }
         
}else{
    // fail
}