Hi,

I am trying to assign an IPV6 address to the interface using SIOCSIFADDR ioctl call. After that trying to bind to that particular IPV6 address added. Bind fails with errno 99 (EADDRNOTAVAIL).
Tried introducing some sleep after ioctl and before bind() call, the same error is returned.

Linux kernel version is 2.6.28.9.

Does anyone know how to fix this??

The program is below:
OUTPUT:

fed1::81
Error: 0
Return of Bind: -1, errno: 99


struct sockaddr_in6 in_addr;
void setIP()
{
struct ifreq ifr;
struct in6_ifreq ifr6;
int socv6;
char ip[50]={0};

memset(&in_addr, 0, sizeof(in_addr));

socv6=socket(AF_INET6, SOCK_DGRAM, 0);
strcpy(ifr.ifr_name,"eth0");
ioctl(socv6, SIOGIFINDEX, &ifr);

ifr6.ifr6_ifindex = ifr.ifr_ifindex;
ifr6.ifr6_prefixlen = 64;

inet_pton(AF_INET6, "fed1::81", &in_addr);
inet_pton(AF_INET6, "fed1::81", &ifr6.ifr6_addr);
inet_ntop(AF_INET6, &in_addr, &ip, sizeof(ip) );

inet_ntop(AF_INET6, &ifr6.ifr6_addr, &ip, sizeof(ip) );
printf("%s:\n", ip);

ioctl(socv6,SIOCSIFADDR,&ifr6);
printf("Error: %d\n",errno);
}
int main()
{
int sockFd=0, ret =0;

setIP();

sockFd = socket(AF_INET6, SOCK_STREAM, 0);
inet_pton(AF_INET6, "fed1::81", &(in_addr.sin6_addr));

int one = 1;

if (setsockopt(sockFd, SOL_SOCKET, SO_REUSEADDR, &one,
sizeof(one)) < 0)
{
printf("ERROR in set_sockopt(): %d\n", errno);
return 0;
}

in_addr.sin6_port = htons(8888);
in_addr.sin6_family = AF_INET6;

ret = bind(sockFd, (struct sockaddr *)&in_addr, sizeof(in_addr));
printf("Return of Bind: %d, errno: %d\n", ret, errno);

getchar();
return 0;
}

thanks in advance,
Lakshmi

Hi,

Found a workaround at this blog http://mwnnlin.blogspot.com/2010/05/...nd-issues.html.

If anyone knows of another solution other than modifying the Kernel source and disabling DAD requests, please reply..

thanks
Lakshmi

It's possible to disable DAD (and thus fix this problem) without patching the kernel. You just need to set net.ipv6.conf.INTERFACE.accept_dad to 0 in sysctl.

For example, before bringing up eth0, run:

If you're using Debian, you can put this in your interfaces file as a "pre-up" command.