Sorry Kingsley, I didn`t understand that 224.0.0.5 in binary is: 11100000 00000000 0000000*0* 00000101
As you said, the 25th bit is 0 as I can see But I didn`t get from now on On Thu, Dec 23, 2010 at 11:31 AM, Kingsley Charles < [email protected]> wrote: > First 24 bits is 01:00:5E. The 25th bit is "0". The last 23 bits are the > last 23 bits of the Multicast IP address. > > > > With regards > Kings > > On Thu, Dec 23, 2010 at 6:00 PM, Bruno <[email protected]> wrote: > >> I know that there is a special block that IANA set aside for the vendor >> part (1st 3 octets) of a multicast MAC address: 00:00:5E. (The addresses >> above start with 01 instead of 00 because the broadcast/multicast bit is >> set. Since this vendor block was set aside for multicast, they will really >> always start off with 01:00:5E.) The rest of the address is somehow >> calculated from the IP address >> >> Any thoughts? >> >> >> On Thu, Dec 23, 2010 at 10:27 AM, Bruno <[email protected]> wrote: >> >>> Taking OSPF as an example, how could they say that the packet sent to >>> 224.0.0.5 will have destination MAC-address 0100.5e00.0005 ? >>> Is there any calculation method I should be aware of >>> >>> Any thought? >>> >>> -- >>> Bruno Fagioli (by Jaunty Jackalope) >>> Cisco Security Professional >>> >> >> >> >> -- >> Bruno Fagioli (by Jaunty Jackalope) >> Cisco Security Professional >> >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> > -- Bruno Fagioli (by Jaunty Jackalope) Cisco Security Professional
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