Re: Multicat MAC Address

From: Edmund Roche-Kelly (edr9007@xxxxxxx)
Date: Tue Apr 16 2002 - 15:46:59 GMT-3


   
set cam static 01-00-5e-01-02-03 [port]

In case you're wondering how multicast layer 2 addresses are
defined....

Multicast layer 2 addresses start with 01-00-5e, have bit 25=0
and use the last 23 bits of the group address.

So 239.1.2.3=11101111.00000001.00000010.00000011
First 25 bits of multicast layer2=00000001.00000000.01011110.0
Adding last 23 bits of IP address gives
00000001.00000000.01011110.00000001.00000010.00000011
Or
01-00-5e-01-02-03

Notice the overlap this creates -- 239.129.2.3 will have the
same layer 2 address, as will 224-239.129.2.3 and 224-239.1.2.3.

See http://www.cisco.com/warp/public/105/mcastguide9.html

Ed

Alex Paulino wrote:
>
> Dear Friends, Does someone know how to set the static MAC address in the cam
table to Multicast address 239.1.2.3?
>
>
> Tks
>
> alex



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