Example: Sending a Multicast Stream
Sending a Multicast Stream with No Directly Attached Hosts
The figure above provides an example of MLD processing on
Extreme Networks devices when there are no directly attached hosts.
- A single IP
multicast server, with no directly attached hosts, sends a multicast stream into the
network via Switch 1.
- Because MLD
snooping is disabled, Switch 1 floods the multicast stream to all ports which are linked
to Router 1 and Router 2.
- Each router
performs an MLD forwarding check to see if there are any hosts that want to join the
multicast group on its locally attached network. Each router drops multicast packets
until a host joins the group using one of the following messages:
- solicited
join (sent in response to an MLD query produced by the router‘s interface)
- unsolicited
join (sent as a request without receiving an MLD query first)
In
Sending a Multicast Stream with No Directly Attached Hosts, this type
of exchange occurs between Router 2 and Host 2 when:
- Host 2 sends a join message to Router 2.
- Router 2 forwards the multicast stream to Host 2.
- When it no longer wants to receive the stream, Host 2 can do one of the
following:
- Send a leave message to Router 2.
- Time out the MLD entry by not responding to further queries from
Router 2.