Subject: [magma] One question on MLD

From: Indranil Bhattacharya <[email-masked]>
Date: Wed, 17 Jun 2009 09:39:28 +0530

Hello,

        I have a question. Should a host/router send MLD reports for
All-hosts, All-routers and solicited-node Multicast address? These
groups are joined by Ipv6. In RFC 3376 I see the below paragraph:

Section 5: Description of the Protocol for Group Members
==========================================
"The all-systems multicast address, 224.0.0.1, is handled as a
special case.  On all systems -- that is all hosts and routers,
  including multicast routers -- reception of packets destined to the
all-systems multicast address, from all sources, is permanently
  enabled on all interfaces on which multicast reception is supported.  No
IGMP messages are ever sent regarding the all-systems
  multicast address."

but in RFC 3810 I do not see anything mentioned. Could anyone answer this
please?

Thanks,
Indranil

---

From: "K.Kawaguchi" <[email-masked]>
Date: Wed, 17 Jun 2009 13:56:46 +0900

Hi,

You can find the sentence in RFC3810.

RFC3810
---
6.  Protocol Description for Multicast Address Listeners

   The link-scope all-nodes multicast address, (FF02::1), is handled as
   a special case.  On all nodes -- that is all hosts and routers,
   including multicast routers -- listening to packets destined to the
   all-nodes multicast address, from all sources, is permanently enabled
   on all interfaces on which multicast listening is supported.  No MLD
   messages are ever sent regarding neither the link-scope all-nodes
   multicast address, nor any multicast address of scope 0 (reserved) or
   1 (node-local).
---

IMHO, All nodes don't touch All-Nodes multicast address by MLD.
All nodes treat all multicast addresses except All-Nodes multicast
address.
MLDv2 routers are the listeners of Solicited-node multicast address,
All-Routers and All-MLDv2-capable multicast routers at least.

Best Regards
--
Kiyoaki Kawaguchi

"Indranil Bhattacharya <[email-masked]>" wrote:

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---

From: Indranil Bhattacharya <[email-masked]>
Date: Thu, 18 Jun 2009 08:18:41 +0530

Hi Kiyoaki Kawaguchi,

                                Thanks for your response. Later I found out
that we have to send send MLD report for solicited-node multicast address
for the snooping switches to work. Otherwise those switches won't be able to
build state.

Thanks,
Indranil