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Re: many to many dup-to option?



> IIRC, specifying an address associated with that network interface
> will not re-write the destination IP in the IP packet, but instead
> just uses ARP to specify the destination MAC at the ether layer?
> 
> Perhaps you could specify the outbound interface with the broadcast
> address, resulting in the packet being sent with a broadcast MAC, such
> that a switch will reliably flood the packet out to all active ports?
> 
I don't know if this is the real behavior when you specify an address
with an interface.  Can anyone verify this?
> Can you explain further why a hub is no longer sufficient?  If you can
> ensure that the only device transmitting to the hub is the host
> sending out the dup-to traffic (perhaps by physically disabling
> transmit lines on the "listen only" ports), then a hub should be able
> to flood out packets from a single talker to multiple listeners at
> wire speed.
>
 
What you suggest sounds reasonable, and I plan on testing it out. 
However, the main reason I'm skeptical that the hub can continue to
handle the job is the large number of packets per second...  Little
soho hubs were never meant to have that many pps going through them
and I would be surprised if they can keep up with the load.  To test
this I will need to do packet counts at source and destination to make
sure everything is making it through.  That's the problem with sending
SPAN traffic to a hub, if there is a collision on the hub, that packet
is lost forever because the SPAN will not retransmit the missed
packets.