blocking mapping agent

Hello guys,
I was testing mapping agent blocking in following topology

R4----R5(s1/1)------(s1/1)R6

OSPF is routing protocol
R5 is mapping agent.
Task says to configure R5 so R6 does not receive RP announcement
On R5 I did:
# access-list 1 deny any
# int s1/1
# ip multicast boundary 1

I tested this knowing this is not a right config. Deny any in access
list should block ALL multicast, at least what I thought. In this case
OSPF hellos should be blocked and OSPF should break. Interestingly,
OSPF works fine and I can see in debug that R5 and R6 send and receive
224.0.0.5 successfully. R6 does not receive mapping agent messages as
expected.

It looks like "ip multicast boundary" does not stop 224.0.0.5.
Is there an implicit permit in command "ip multicast boundary", Is it
for all 224.0.0.0/24 ?

Thanks,

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Received on Sun Aug 28 2011 - 00:21:55 ART