---
title: "sock_join_multicast_v6()"
description: "The sock_join_multicast_v6() function allows a socket to join a specified multicast IPv6 group on a specific interface."
url: "https://wasix.org/docs/api-reference/wasix/sock_join_multicast_v6/"
markdown: "https://wasix.org/docs/api-reference/wasix/sock_join_multicast_v6.md"
---

# `sock_join_multicast_v6()`

Joins a particular multicast IPv6 group.

## Description

The `sock_join_multicast_v6()` function allows a socket to join a specified multicast IPv6 group on a specific interface.

## Syntax

```ebnf
  ;;; Joins a particular multicast IPv6 group
  (@interface func (export "sock_join_multicast_v6")
    ;;; Socket descriptor
    (param $fd $fd)
    ;;; Multicast group to joined
    (param $multiaddr (@witx const_pointer $addr_ip6))
    ;;; Interface that will join
    (param $interface u32)
    (result $error (expected (error $errno)))
  )
```

## Parameters

- `ctx`: A mutable reference to the function environment.
- `sock`: The socket descriptor.
- `multiaddr`: A WebAssembly pointer to the IPv6 multicast group to be joined.
- `iface`: The interface index to join the multicast group.

## Return Value

The function returns an `Errno` value indicating the outcome of the operation. If the operation is successful, `Errno::Success` is returned. If an error occurs, an appropriate `Errno` value is returned.

## Notes

- The `sock_join_multicast_v6()` function allows a socket to join a specified multicast IPv6 group on a specific interface.
- The `multiaddr` parameter specifies the IPv6 multicast group to join.
- The `iface` parameter specifies the interface index on which to join the multicast group.
- The behavior and limitations of the `sock_join_multicast_v6()` function may vary depending on the specific runtime environment and underlying networking implementation. It is important to consult the documentation or specifications of the specific environment to understand its behavior in that context.

---

[Documentation index](https://wasix.org/llms.txt) · [HTML version](https://wasix.org/docs/api-reference/wasix/sock_join_multicast_v6/)