Re: Regarding Multicasting

Thanks everyone..Groupstudy really rocks..

Appreciate all the help...

thanks
raghav

On Tue, Jun 2, 2009 at 12:44 AM, Lejoe <styran_at_gmail.com> wrote:

> Hi Raghav
>
> I have couple of queries in Mulitcasting:-
>
>>
>> PIM-DM
>>
>> 1. If we have a route coming via Fast Ethernet as well as Serial Interface
>> but it is preferred via Fast Ethernet due to low cost in OSPF. Now using
>> PIM
>> - DM while doing the RPF check we find that the route should come via
>> Serial
>> Interface, so we have 2 options there:-
>>
>> ----> Change the cost on Fast Ethernet link so that it prefers
>> Serial
>> interface *OR*
>> ----> Configure a static mroute entry for that route pointing to the
>> next hop which should be serial interface.
>>
>> Now lets say I use the static route option. when I configure my router
>> everything works RPF check succeeds etc etc. What my query is should i see
>> that route in the IGP Routing table to come via Serial Interface or Fast
>> Ethernet interface coz earlier it was coming via Fast Ethernet ? Also
>> whatever is the answer why??
>
>
> *mroute does not affect the IGP routing table. It is only used decide the
> RPF information.*
> So you wont see any changes to your IGP routing table.
>
>
>>
>> PIM- SM
>>
>> 1. We are using static RP configuration on all the routers . now lets say
>> if
>> on one of my routers I have 2 Fast ethernet interfaces i.e Fa0/0, Fa0/1.
>> Now
>> only Fa0/0 is configured for PIM- SM. My questions are:-
>>
>> -------> If I configure IGMP Join group 224.1.1.1 on this router , I
>> will also have to configure the configuration for static RP i.e ip pim
>> rp-address x.x.x.x 1 along with the access-list permitting that multicast
>> IP.
>> Because what i know is that when we use static RP we have to configure it
>> on
>> all the Routers coz otherwise the Routers will not know who the RP is . So
>> even If we configure the IGMP join-group command on this router do we also
>> need the static RP config. Please correct me If I am wrong??
>
>
> *Having configured pim sparse mode. The PIM router needs to send join
> messages towards
> the RP. Without this, how will it receive multicast traffic, since by
> definition sparse mode sends only
> multicast traffic to routers that request it.*
>
>>
>>
>> -------> Second question is since PIm- SM is not enable on Fa0/1 , can
>> I configure IGMP-JOIN group command on this interface. Also something to
>> note here is there is no ip address. Can we do this???
>> I am kinda confused in this one.
>
> *
> Now since the router is already receiving multicast traffic (int f0/0 in
> sparse-mode and RP configured)
> You can enable ip igmp join-group on fa0/1 so it joins the multicast group.
> However ,an ip address
> is also necessary without which it will be not able to respond to IGMP
> queries or send IGMP membership
> reports and hence cannot join the multicast group.*
>
>
> Lejoe
>
>

-- 
Warm Regards
Raghav
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