# Method Stdio.UDP()->drop_membership()

Method drop_membership

  ``int` drop_membership(`string` `group`, `void`|`string` `address`)`

Description

  Leave a multicast group.

Parameter `group`

  `group` contains the address of the multicast group the application wants to join. It must be a valid multicast address.

Parameter `address`

  `address` is the address of the local interface with which the system should join to the multicast group. If not provided the system will select an appropriate interface.

  See also the Unix man page for setsocketopt IPPROTO_IP IP_DROP_MEMBERSHIP and IPPROTO_IPV6 IPV6_LEAVE_GROUP.

Note

  The `address` parameter is currently not supported for IPv6.

Note

  This function did not support IPv6 in Pike 7.8 and earlier.

See also

  add_membership()