Re: Dircetd broadcast

Bob your explanation is clear .Thank you !!

On Thu, Dec 16, 2010 at 11:15 PM, Jack Router <pan.router_at_gmail.com> wrote:

> Thanks to all who replied. BTW, I finally understood what for is "ip
> directed broadcast" :)
>
>
> On 16 December 2010 16:13, Bob Sinclair <bob_at_bobsinclair.net> wrote:
>
> > 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.
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
> >
> >
> >
> >
> >
> > ------------------------------
> >
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 10.0.1170 / Virus Database: 426/3319 - Release Date: 12/16/10
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Fri Dec 17 2010 - 13:48:07 ART