ZeroMQ is not working over unicast IPv6 - c++

Question

I'm in a trouble with ZeroMQ and IPv6. When I use a connection through IPv4 or if I use "tcp://[::1]:5558", it connects like a charm. However, if I use the server full IPv6 address (on my local host or remote host) it connects, but don't get data on the other endpoint.
Here is my code sample:
client.cpp
#include <stdio.h>
#include <zmq.h>
int main(int argc, char** argv)
{
void* context = zmq_ctx_new();
void* socket = zmq_socket(context, ZMQ_SUB);
int ipv6 = 1;
zmq_setsockopt(socket, ZMQ_IPV6, &ipv6, 4);
zmq_connect(socket, "tcp://[fe80::52e5:49ff:fef8:dbc6]:5558");
//zmq_connect(socket, "tcp://[::1]:5558");
zmq_setsockopt(socket, ZMQ_SUBSCRIBE, "pub", 3);
zmq_msg_t message;
do {
zmq_msg_init (&message);
zmq_msg_recv (&message, socket, 0);
printf("%s\n", (char*)zmq_msg_data(&message));
zmq_msg_close(&message);
} while (zmq_msg_more(&message));
}
And server.cpp
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <zmq.h>
int main(int argc, char**argv)
{
void* context = zmq_ctx_new();
void* publisher = zmq_socket(context, ZMQ_PUB);
int ipv6 = 1;
zmq_setsockopt(publisher, ZMQ_IPV6, &ipv6, sizeof(int));
zmq_bind(publisher, "tcp://*:5558");
char buffer[4] = "pub";
unsigned tries = 0;
while(tries < 10) {
zmq_send(publisher, &buffer, strlen(buffer), 0);
tries++;
sleep(1);
}
return 0;
}
I'm using ZeroMQ 4.0.0 RC, but it is also happening on 3.2. I'm on linux (slackware) and installed it from sources. I also tested using a java server using jeroMQ and the problem is the same. I did another test using a REQ-REP connection and the problem is the same.
Thanks in advance for any help.

Answer 1

fe80* addresses are link local, you must specify the local hosts link name: e.g. fe80...:1%eth1
fe80::/10 — Addresses in the link-local prefix are only valid and
unique on a single link. Within this prefix only one subnet is
allocated (54 zero bits), yielding an effective format of fe80::/64.
The least significant 64 bits are usually chosen as the interface
hardware address constructed in modified EUI-64 format. A link-local
address is required on every IPv6-enabled interface—in other words,
applications may rely on the existence of a link-local address even
when there is no IPv6 routing. These addresses are comparable to the
auto-configuration addresses 169.254.0.0/16 of IPv4.
http://en.wikipedia.org/wiki/IPv6_address#Local_addresses