Hi, I am reposting the qwestion hoping that somebody can help me.
In brief I would like to know how is that netmon uses the -J option to
generate a broadcast in the remote networks? Is it a directed
broadcast to the subnet brodcast address?
Thanks
Quoting igastelu@unm.edu:
> Hi, I would like to know how the -J option causes the broadcast in
> the
> local network. From the manual(NV for NT):
> -J Causes netmon to attempt to speed the process of discovering new
> nodes at the expense of limited broadcast traffic. When a new network
>
> or subnet is first discovered, netmon causes the first sufficiently
> capable node it discovers in that network or subnet to broadcast an
> ICMP Echo request. Thereafter, while the network or subnet remains in
>
> the map, netmon causes no additional broadcasts to be generated
> there.
>
> However, most of us does not respond to ICMP echos to our subnets
> broadcast addresses('no ip-directed broadcast' on Cisco). I suspect
> the
> reason to create a broadcast once an SNMP capable host is discovered
> is
> to retrieve a fresh ARP table with all the actives host on it, but I
>
> can not see how it is done. Is it a spoofed IP datagram with the
> source IP address changed to the IP of the remote SNMP capable host?
> I hope the question is not out of order.
> Thanks for your help
>
> Inaki
>
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