See, I know that a normal switch will treat the multicast as a broadcast,
but if I wanted ONLY to send the data to stations participating in the
multicast group, I would need to have something like IGMP running on the
router and CGMP on the switch, unless there's another way to do it, which
could be descriped later in the chapter.
The reason why I actually broad this up, was because I started thinking
about a scenario where you have a very small company with only one LAN (or
VLAN for those of you who like to use that term) and NO router. It would
seem a waste of power and money to purchase a router only for the purpose of
not sending out multicast data to non-multicast-participating workstations.
Thanks,
Ole
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ole Drews Jensen
Systems Network Manager
CCNA, MCSE, MCP+I
RWR Enterprises, Inc.
[EMAIL PROTECTED]
http://www.oledrews.com/ccnp
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NEED A JOB ???
http://www.oledrews.com/job
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----Original Message-----
From: Evan Francen [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, January 17, 2001 3:09 PM
To: 'Ole Drews Jensen'; '[EMAIL PROTECTED]'
Subject: RE: Multicast: Router and Switch locations
You would not have to setup the router with ip multicast-routing (IGMP),
unless the multicast server and clients are in seperate VLANs. The
workstation doesn't need to tell the router that it joined the group when
the server and clients are in the same VLAN. The server will just send the
multicast data to a specific multicast group (224.0.0.1 - 239.255.255.255),
then the clients listening for that group address will respond. Switches
forward mulicast data out all ports except the one that the data was
received on.
I would think that with 10 clients on the switch, it would be overkill to
add another router. Multicasting will work fine with only a switch, the
traffic will just be forwarded through all ports. If you have separate
VLANs, then turn on multicast routing on the switch, choose your PIM mode,
and enable CGMP. The router uses CGMP to aid the switch in building the CAM
table for multicast traffic.
HTH,
Evan
-----Original Message-----
From: Ole Drews Jensen [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, January 17, 2001 1:38 PM
To: '[EMAIL PROTECTED]'
Subject: Multicast: Router and Switch locations
Currently reading about Multicast, which I have not any experience with yet.
If you have a small simple LAN with 1 fileserver, 10 workstations and 1
router to the Internet:
INTERNET---[router]---[switch]---[fileserver & 10 workstations]
In order for that fileserver to send multicast data to participating
workstations without changing the topology, I would have to setup the router
with IGMP and CGMP, so the workstation could tell the router that it joined
a group, and the router could then inform the switch with CGMP about that
workstation. The fileserver would now send multicast data and the switch
would know which interface(s) to forward it out to.
Since the server and every workstation has their own connection to the
switch (and hence has their own individual collision domain), would I be
right in assuming that it would not improve the situation to add an
additional router to act like a filter between the switch and the server?
INTERNET---[router]---[switch]---[10 workstations]
|
[router2]
|
[fileserver]
Also, will we see multicasting work without a router or an rsm but only with
a switch in the future (I know that switches don't understand IGMP)?
Thanks,
Ole
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ole Drews Jensen
Systems Network Manager
CCNA, MCSE, MCP+I
RWR Enterprises, Inc.
[EMAIL PROTECTED]
http://www.oledrews.com/ccnp
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NEED A JOB ???
http://www.oledrews.com/job
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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