Hi Swaroop / Mayers, Thanks for the information.
Regards Vikas Sharma On 6/29/07, Swaroop Potdar <[EMAIL PROTECTED]> wrote: > > Well then i believe it sums up the story for the original poster. > > I took care of the LAN (IGMP Snooping) and you took care of the WAN (PIM > Snooping). > > :-) > > ------------------------------ > *From:* Phil Mayers [mailto:[EMAIL PROTECTED] > *Sent:* Fri 6/29/2007 7:30 AM > *To:* Swaroop Potdar > *Cc:* Vikas Sharma; [email protected] > *Subject:* RE: [c-nsp] Multicast MAC address > > > > On Fri, 2007-06-29 at 06:06 -0500, Swaroop Potdar wrote: > > Most WAN media types are P2P in nature so there is no Multicast to MAC > > mapping. > > Well yes, but since the OP mentioned multicast MAC addresses, it was a > pretty safe bet to assume he was talking about Ethernet > > > > > Since ethernet is a broadcast and multiple access type media in > > nature, the multicast to mac address mapping is desired to avoid > > flooding of traffic to all hosts connected to the media. > > > > So when you enable IGMP Snooping on a Layer 2 switch it makes a note > > of all the IGMP requests and converts them to mac equivalent and > > stores in the cam table. and also reports the same to the router, then > > the router forwards the traffic feed to the switch and the traffic > > reaches to the end destinatiosn which had requested the group, but the > > destination address is the multicast-mac address when it is sent to > > the end host, hence not everybody receives the traffic, but only the > > hosts which sent the igmp join will receive the traffic. > > Sure - but in an ethernet-as-wan-link setting, IGMP is not likely to be > in use, it's more likely to be PIM - and PIM snooping (or set > multicast=flood) is needed if a layer2 hop exists between the two layer3 > endpoints. > > > > > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
