RE: Dircetd broadcast

Hi Jack,
 
It is going out as a broadcast because the router is directly connected to
the destination network. To see an x.x.x.255 destination address ping a
network that is not connected. This is why it is sometimes called a "letter
bomb"; it is unicast until it gets to its destination, then it explodes as
a broadcast.
 
HTH,
 
Bob Sinclair CCIE 10427 CCSI 30427
www.bobsinclair.net
 
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of Jack
Router
Sent: Thursday, December 16, 2010 3:46 PM
To: ccielab_at_groupstudy.com
Subject: Dircetd broadcast
 
Is it possible to ping directed broadcast address from cisco router? It
looks like directed broadcast is translated to 255.255.255.255 and it does
not matter if "ip directed-broadcast" is enabled or not. Debug ip packet
shows the following:

R1#ping 10.1.12.255
*Mar 1 00:21:12.087: IP: s=10.1.12.1 (local), d=255.255.255.255
(FastEthernet0/0), len 100, sending broad/multicast.

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Received on Thu Dec 16 2010 - 16:13:54 ART