Kings,
try to set three (three, not 2) routers talking OSPF over a LAN,
use crypto with permit ospf on phy interfaces. You'll see that, while
in the case of only two routers the OSPF works (and multicast is
encapsulated IP[ESP[mcastIP]], then, adding the 3rd router everyting
breaks apart.
To make it work you create static VTIs (i.e. p2p links) between three
peers with mode and protection set to ipsec. Note how OSPF will change
from bcast to p2p type...

This proves the conclusion that to make multicast work over
ipsec you need p2p mesh between peers.
===================================


On 7 March 2012 07:17, Joe Astorino <[email protected]> wrote:
> I was talking about multicast as a destination IP address in the
> original IP header.
>
> On Wed, Mar 7, 2012 at 1:03 AM, Kingsley Charles
> <[email protected]> wrote:
>> If you have "permit ip any any", crypto maps will encrypt multicast
>> and I have confirmed it with wireshark using AH.
>>
>>
>> Here, we are talking about two things - Multicast in the payload and
>> Multicast in the IPsec IP header.
>>
>> Multicast in the IPsec IP header has not been addressed in the rfcs.
>> Are we talking about that?
>>
>>
>> With regards
>> Kings
>>
>> On Tue, Mar 6, 2012 at 10:17 PM, Peter Debye <[email protected]> wrote:
>>> We were able to protect IP multicast with good old IPSEC cryptomaps
>>> when applying them to GRE tunnels. Functionally, there's no
>>> difference with the newer VTI. For GRE tunneled traffic you
>>> said "permit all gre" in your crypto, and then the traffic to protect
>>> was chosen according to IP routing tables for unicast or multicast.
>>> The same way you say: "permit all ip sent to VTI".
>>> Pobably, your question is: Why do we need a tunnel interface
>>> in both cases? Why don't we apply a multicast crypto to a physical
>>> interface directly? -- I guess that for multicast implemented the way
>>> we are discussing we need p2p interfaces between peers. The physical
>>> router interfaces are not in p2p mode in all cases. Imagine what will
>>> happen if you have several routers connected to a LAN...
>>>
>>> =============================================
>>>
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