IGMP Routines

IGMP Routines enable IP Multicasting. More...

Functions
netStatus	igmp_join (uint32_t if_num, const uint8_t *ip_addr)
	Join this host to a host group specified with IP address.
netStatus	igmp_leave (uint32_t if_num, const uint8_t *ip_addr)
	Leave a host group specified with IP address.

Description

IGMP Routines enable IP Multicasting.

IGMP routines enable you to use IP Multicasting - the transmission of an IP datagram to a "host group". A multicast datagram is delivered to all the members of its destination host group. IGMPv1 and IGMPv2 protocol specification is supported in the Network Component.

Function Documentation

netStatus igmp_join	(	uint32_t	if_num,
		const uint8_t *	ip_addr
	)

Join this host to a host group specified with IP address.

Parameters

[in]	if_num	interface number.
[in]	ip_addr	group IP address.

Returns

status code that indicates the execution status of the function as defined with netStatus.

The function igmp_join requests that a host should become a member of the host group identified by ip_addr.

The argument if_num is the interface number of the host.

The argument ip_addr points to the address of the group. Before any datagrams destined to a particular group can be received, an upper-layer protocol must ask the IP module to join that group.

Code Example

const uint8_t sgroup[4] = { 238, 0, 100, 1};
 ..
if (igmp_join (0, sgroup) == netOK) {
  printf ("This Host is a member of group: %d.%d.%d.%d\n",
           sgroup[0],sgroup[1],sgroup[2],sgroup[3]);
}
else {
  printf ("Failed to join a host group.\n");
}
 ..

netStatus igmp_leave	(	uint32_t	if_num,
		const uint8_t *	ip_addr
	)

Leave a host group specified with IP address.

Parameters

[in]	if_num	interface number.
[in]	ip_addr	group IP address.

Returns

status code that indicates the execution status of the function as defined with netStatus.

The function igmp_leave requests a host to give up its membership in a host group.

The argument if_num is the host interface number.

The argument ip_addr points to the host group. After the upper-layer has requested to leave the host group, datagrams destined to a particular group can not be received, but are silently discarded by the IP-layer.

Code Example

const uint8_t sgroup[4] = { 238, 0, 100, 1};
 ..
if (igmp_leave (0, sgroup) == netOK) {
  printf ("This Host has left the group: %d.%d.%d.%d\n",
           sgroup[0],sgroup[1],sgroup[2],sgroup[3]);
}
else {
  printf ("Failed to leave a group, this host is not a member.\n");
}