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# nw_group_descriptor_create_multicast(_:)

Creates group descriptor you use to join an IP multicast group on a local network.

```
func nw_group_descriptor_create_multicast(_ multicast_group: nw_endpoint_t) -> nw_group_descriptor_t
```

## Discussion

> Important:
> In order to use multicast on iOS, your app will need to have the `com.apple.developer.networking.multicast` entitlement.

## Topics

### Customizing Multicast Behavior

[`nw_multicast_group_descriptor_set_disable_unicast_traffic(_:_:)`](/documentation/Network/nw_multicast_group_descriptor_set_disable_unicast_traffic(_:_:))

Sets a Boolean that indicates whether a connection group should reject unicast traffic.

[`nw_multicast_group_descriptor_get_disable_unicast_traffic(_:)`](/documentation/Network/nw_multicast_group_descriptor_get_disable_unicast_traffic(_:))

Checks a Boolean that indicates whether a connection group should reject unicast traffic.

[`nw_multicast_group_descriptor_set_specific_source(_:_:)`](/documentation/Network/nw_multicast_group_descriptor_set_specific_source(_:_:))

Sets an optional address endpoint used to filter received multicast packets.


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