From: Scott Morris (smorris@ipexpert.com)
Date: Sun Oct 21 2007 - 18:43:18 ART
1. For testing purposes (which I believe is where the PG puts in the igmp
join-group commands) you'd use that. It's just a quick way to test the
multicast operation with pings. Not specifically required by the task
though.
2. You need to have PIM enabled in order to enable IGMP period (show ip
igmp interfaces to look). Then the helper-address forwards it on. The pimg
neighbor filter is a way to 'warn' the upstream that it'll be forwarded
messages and not to expect a full PIM relationship.
http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cg/himc_c
/chap10/mcbcigmp.htm#wp1091587
HTH,
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE-M
#153, JNCIS-ER, CISSP, et al.
CCSI/JNCI-M/JNCI-ER
VP - Technical Training - IPexpert, Inc.
IPexpert Sr. Technical Instructor
A Cisco Learning Partner - We Accept Learning Credits!
smorris@ipexpert.com
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-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
George Goglidze
Sent: Sunday, October 21, 2007 1:02 PM
To: Cisco certification
Subject: IPEXPERT Section 15, Multicast
Hello all,
I'm doing ipexperts section 15 multicast lab, and have couple questions
please.
1) They tell you, for example, on R1 F0/0 you have source for multicast
groups 224.11.11.11.
and you have to announce it automatically.
I do autorp with access-lists to filter only the groups I need, and it works
just fine.
but when I see solution, I see that on the F0/0 interface they have ip igmp
join-group 224.11.11.11 !!!
is this really necessary ??? because I think this could be for testing
purposes.
but if they don't ask you to join the group in a task, you do not really
need to join it do you?
2) they tell me to make the R8 stub router. R8 has source on it's f0/0
224.88.88.88
and everyone needs to see R7 as RP for this multicast source.
so what you do is, on R8 f0/0 put ip igmp helper-address <R7 ip address> and
then that's it. you don't even need to configure pim on R8!!!
all igmp messages will be forwarded to R7, and that's it.
but they did configure pim on all interfaces on R8, and on R7 they filtered
with ip pim neighbor-filter.
which I think is not necessary.
I need your opinion please,
Thank you very much,
This archive was generated by hypermail 2.1.4 : Fri Nov 16 2007 - 13:11:17 ART