Multicast - ip igmp join-group 'ip address' command

gatecrash · ‎06-20-2016

Hello,

I have been following a tutorial for some multicast configuration. What I do not understand is how do we determine the ip address for the client to subscribe to if they want to receive multicast traffic? The below config specify 239.4.4.4 but the tutorial did not explain where that ip is plucked from.

Can anyone explain? Thanks.

router#conf t
router(config)#ip multicast-routing
router(config)#ip pim autorp listener
router(config)#int s1/0
router(config-if)#ip pim sparse-mode
router(config-if)#ip igmp join-group 239.4.4.4
router(config-if)#end

paul driver · ‎06-21-2016

Hello

239.0.0.0/8 is an admin scoped address range just like the ipv4 1918 rfc privates addressing

It seems in this case the tutorial is using an ip in this range for testing purposes and is specifying a MC receiver so you test response to pings.

res
Paul

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Paul

gatecrash · ‎06-21-2016

Hello Paul,

Thanks so am I right to say the admin scoped address is specified on the multicast server (windows server for example)? In that case then i understand why the server config is left out as he is focusing on the networking aspect of multicast. I was looking for the command to point or direct traffic to 239.4.4.4 but couldn't find it.