I understande how Multicast routers should not forward any multicast datagram with destination addresses in this range (224.0.0.0 - 224.0.0.255 ) bec. of ttl not able the address to go to the next hop. But I dont' remember how those addresses are translated to L2 addresses. Or maybe I'm not reading into it...or the link local terminology is throwing me off.
Thanks all for you answers. rbx10Priscilla Oppenheimer wrote: > > rbx10 Defcom wrote: > > > > Hi everyone, > > I was wondering if someone can explain to me what is > > "Link-Local to L3 to L2 mapping" under Cisco R&S Blue print > > under In the IP Multicast Section. > > My guess is that you don't have the phrase quite right. :-) > It's probably "link local L3-to-L2 mapping" and simply means > the normal method that you probably already know to translate a > multicast IP address to a MAC address. > > Try this URL: > > http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/ipmulti.htm > > Link-local means the address is only used locally. It's used > for packets that have a TTL of 1. IPv6 has such a concept and I > think the term came from there, but I don't think Cisco is > referring to IPv6 here. > > IANA, the gods of all Internet related numbers, has subdivided > the IP multicast address space. More here at the IANA site: > > http://www.iana.org/assignments/multicast-addresses > > 224.0.0.0 - 224.0.0.255 (224.0.0/24) is the Local Network > Control Block and I think that's what Cisco is referring to. > It's reserved for the use of routing protocols and other > low-level > topology discovery or maintenance protocols. Multicast routers > should not forward any multicast datagram with destination > addresses in this range > > So, do you know how those addresses are translated to L2 > addresses? It's not anything you haven't heard before, > especially if you studied for the Switching exam. At least as > far as I know, the translation isn't any different for these > just because Cisco calls them "link local." Hopefuly somebody > will correct me if I'm wrong, though. > > Priscilla > > > > > > > > > I read Jeff Doyle II on IP Multicasting and other materials on > > IP Multicast but I can't seem to depict that concept. Could > > someone point me in the direction ? > > > > Thanks for all your help. > > > > RBX10- > > TAKING THE TEST NEXT WEEK !!! :-) > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=71608&t=71577 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
