On 19/01/2011 01:52, Marcy Cortes wrote:
Thanks Scott, Philip, and Alan,
That gives me enough info. Curious though how to map the mac addr to
the IP from Linux itself? They don't show up in arp -n . Would one
check at the router?
There's a defined many -> one mapping from IP multicast addresses to MAC
addresses which begin 01:00:5E: (or 33:33: for IPv6).
http://www.tcpipguide.com/free/t_TCPIPAddressResolutionForIPMulticastAddresses.htm
http://en.wikipedia.org/wiki/Multicast_address#Ethernet
You can't map back directly from MAC address to IP though, as some bits
were dropped in the IP->MAC mapping. I assume (speculation follows) that
this scheme helps unburden the kernel by programming the network
hardware with interesting MAC addresses, ignoring otherwise irrelevant
packets.
Cheers,
Phil
----------------------------------------------------------------------
For LINUX-390 subscribe / signoff / archive access instructions,
send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit
http://www.marist.edu/htbin/wlvindex?LINUX-390
----------------------------------------------------------------------
For more information on Linux on System z, visit
http://wiki.linuxvm.org/
