Windows 10: getaddrinfo - connect UDP IPv6 to IPv4

Hi there,


I tried to connect a local IPv6 UDP socket to a remote IPv4 IP, as follows:


#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <errno.h>

#include <iostream>



#include <winsock2.h>

#include <Ws2tcpip.h>

#include <io.h>





int getUdpAddrInfo_const std::string &ip, const std::string &port, addrinfo **result

{

struct addrinfo hints;

memset&hints, 0, sizeofstruct addrinfo;

hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */

hints.ai_family = AF_UNSPEC; /* Allow IPv4 and IPv6 */

// For Linux and Windows Vista onwards, further specify options

hints.ai_flags = AI_V4MAPPED AI_ALL AI_ADDRCONFIG; /* For wildcard IP address */

hints.ai_protocol = IPPROTO_UDP; /* UDP protocol */

hints.ai_canonname = NULL;

hints.ai_addr = NULL;

hints.ai_next = NULL;



int const s = getaddrinfo

/* ip */ ip.data,

/* port */ port.data,

/* hints */ &hints,

/* list */ result;

return s;

}





int main int argc, char *argv[]

{

WORD wVersionRequested = MAKEWORD2, 2;

WSADATA wsaData;

int const wsaStartupStatus = WSAStartupwVersionRequested, &wsaData;



std::string const ipLocal"::";

std::string const portLocal"1234";



std::string const ipRemote"127.0.0.1";

std::string const portRemote"2345";



struct addrinfo *result;

int s = getUdpAddrInfo_ipLocal, portLocal, &result;

if s != 0

{

exit1;

}



SOCKET connectedSocket = INVALID_SOCKET;

if nullptr == result

{

exit1;

}



struct addrinfo *rp = nullptr;

for rp = result; rp != NULL; rp = rp->ai_next

{

SOCKET sock = socketrp->ai_family,

rp->ai_socktype,

rp->ai_protocol;



if INVALID_SOCKET == sock

{

continue;

}

else

{

if AF_INET6 == rp->ai_family

{

DWORD const ipv6Only = 0; // 0 - false

int const errorCode = setsockoptsock, IPPROTO_IPV6, IPV6_V6ONLY, char const *&ipv6Only, sizeofipv6Only;

if NO_ERROR != errorCode

{

exit1;

}

}

if bindsock, rp->ai_addr, rp->ai_addrlen == NO_ERROR

{



// connect

struct addrinfo *result2;

int const s2 = getUdpAddrInfo_ipRemote, portRemote, &result2; // 1

if s2 != 0

{

exit1;

}



struct addrinfo *rp2 = nullptr;

bool connected = false;

if result2

{

for rp2 = result2; rp2 != NULL; rp2 = rp2->ai_next

{

if connectsock, rp2->ai_addr, rp2->ai_addrlen == NO_ERROR

{

connected = true;

break;

}

}

}

freeaddrinforesult2;





if connected

{

connectedSocket = sock;

break;

}

}

else

{

closesocketsock;

}

}

}



freeaddrinforesult; /* No longer needed */



std::cout << "socket: " << connectedSocket << std::endl;



closesocketconnectedSocket;



WSACleanup;



exit0;

}


The getUdpAddrInfo_ at 1 however only returns an IPv4 and no IPv6-mapped IPv4 address.


If I instead set


hints.ai_family = AF_INET6;



then the IPv4-mapped IPv6 address is returned as desired. Do I have to explicitely check what kind of socket I want to connect and ask for an appropriate address? Why does it not return the IPv6-mapped IPv4 address?


Best regards,


Johannes

:)

 

Connectivity (IPv4/IPv6): Disconnected

Hi,



Thank you for writing to Microsoft Community Forums.



Ideally this Connectivity (IPv4/IPv6): Disconnected, means that the devices in not in use or not connected and it could be any device for example, Ethernet, WIFI, Bluetooth or Local Area Connection.



If you are using WI-FI for internet connection then Ethernet will show Connectivity (IPv4/IPv6): Disconnected.



In order to understand the issue and assist you accordingly, we need some information

• What is your network setup?
  
• Are you seeing any errors?
  
• Where you are seeing this information?

Meanwhile, try the troubleshooting steps referred in this article:

Fix network connection issues in Windows and check if it works.



Regards,

Aditya Roy

Microsoft Community – Moderator

 

ipv4 connected ipv6 no network access

So I thought my problem was solved, and then just now my internet stopped working again. Same problem, ipv4 connected ipv6 no network access. Anyone have any suggestions?

 

Connectivity (IPv4/IPv6): Disconnected

Name: Ethernet

Description: Realtek PCIe GBE Family Controller

Physical address (MAC): ec:8e:b5:d6:e4:0b

Status: Not operational

Maximum transmission unit: 1500

IPv4 address: 169.254.250.35/16

IPv6 address: fe80::8408:262a:dd06:fa23%12/64

DNS servers: 192.168.1.254, 75.153.171.122

DNS connection suffix: telus

Connectivity (IPv4/IPv6): Disconnected





Name: Wi-Fi

Description: Realtek RTL8723BE 802.11 bgn Wi-Fi Adapter

Physical address (MAC): cc:b0:da:45:99:2b

Status: Not operational

Maximum transmission unit: 1500

IPv4 address: 169.254.90.214/16

IPv6 address: fe80::853f:94b6:aeb2:5ad6%15/64

DNS servers: 192.168.43.1

Connectivity (IPv4/IPv6): Disconnected





Name: Local Area Connection* 12

Description: Microsoft Hosted Network Virtual Adapter

Physical address (MAC): 48:f8:b3:97:96:cb

Status: Not operational

Maximum transmission unit: 1500

IPv4 address: 169.254.184.142/16

IPv6 address: fe80::a415:bde6:5709:b88e%20/64

DNS servers: fec0:0:0:ffff::1%1, fec0:0:0:ffff::2%1, fec0:0:0:ffff::3%1

Connectivity (IPv4/IPv6): Disconnected





Name: Wi-Fi 2

Description: Linksys AE1200

Physical address (MAC): 48:f8:b3:97:96:cb

Status: Operational

Maximum transmission unit: 1500

Link speed (Receive/Transmit): 144/104 (Mbps)

DHCP enabled: Yes

DHCP servers: 192.168.1.254

DHCP lease obtained: ‎November ‎1, ‎2018 4:03:27 PM

DHCP lease expires: ‎November ‎2, ‎2018 4:03:27 PM

IPv4 address: 192.168.1.67/24

IPv6 address: 2001:56a:f2d7:3800:29ed:7176:fa4f:7afa/64, 2001:56a:f2d7:3800:a588:1afb:4da:872e/128, fe80::29ed:7176:fa4f:7afa%3/64

Default gateway: fe80::72f1:96ff:fe5c:2dd0%3, 192.168.1.254

DNS servers: 2001:568:ff09:10c::53, 2001:568:ff09:10b::122, 192.168.1.254, 75.153.171.122

DNS domain name: telus

DNS connection suffix: telus

DNS search suffix list:

Network name: TELUS4370

Network category: Private

Connectivity (IPv4/IPv6): Connected to Internet





Name: Bluetooth Network Connection

Description: Bluetooth Device (Personal Area Network)

Physical address (MAC): cc:b0:da:45:99:2c

Status: Not Present

Maximum transmission unit: 0

Connectivity (IPv4/IPv6): Disconnected





Name: Local Area Connection* 10

Description: Microsoft Wi-Fi Direct Virtual Adapter

Physical address (MAC): ce:b0:da:45:99:2b

Status: Not Present

Maximum transmission unit: 0

Connectivity (IPv4/IPv6): Disconnected





Name: Local Area Connection* 11

Description: Microsoft Wi-Fi Direct Virtual Adapter #2

Physical address (MAC): cc:b0:da:45:99:2b

Status: Not Present

Maximum transmission unit: 0

Connectivity (IPv4/IPv6): Disconnected