From: Brian McGahan (bmcgahan@internetworkexpert.com)
Date: Mon Nov 08 2004 - 14:03:07 GMT-3
Tim,
Only the last-hop router of a transmission knows whether a
packet is a directed broadcast or not. This is due to the fact that
other routers in the transit path may or may not know what the actual
subnet mask of the final segment is. Therefore, the "ip
directed-broadcast" statement only affects the last hop router as it
tries to send a directed broadcast on to the segment itself, not to
route it through the network.
HTH,
Brian McGahan, CCIE #8593
bmcgahan@internetworkexpert.com
Internetwork Expert, Inc.
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> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> ccie2be
> Sent: Monday, November 08, 2004 9:46 AM
> To: Group Study
> Subject: ip directed-broadcast
>
> Hi all,
>
> When the above command is entered on an interface which packet flow is
> affected? Packets coming into the interface from the attached subnet
or
> packets leaving the interface onto the attached subnet or both?
>
> Also, can debug ip packet to verify this or, if not, how can I verify
> this?
>
> By default, ip directed-broadcast is disabled but it's needed when
using
> multicast helper maps and I keep forgetting on which interfaces it
needs
> to
> be
> enabled.
>
> TIA, Tim
>
>
This archive was generated by hypermail 2.1.4 : Thu Dec 02 2004 - 06:57:40 GMT-3