From: glen herrmannsfeldt on
In comp.protocols.tcp-ip markp <map.nospam(a)f2s.com> wrote:
(snip, someone wrote)

>> No no, you are correct on that. I was just looking for some readily
>>available utility, I avoid wintel programming like the plague, just
>>the thought of their APIs etc. stuff makes me sick.
(snip)

> Ahha, you're after some already existing software to map MAC
> addresses to IP addresses.

> If you open a command box in XP and type 'arp -a' you get a list of MAC
> addresses and their associated IP addresses. Is that what you want? you
> could easily write a batch file to scan for a given MAC address or dump to a
> file to search.

Some will respond to a ping to the broadcast address, others not.

It seems that it you want to be found then you should respond.

Then you can ping to the broadcast address, followed by arp -a
to see who replied.

-- glen
From: glen herrmannsfeldt on
In comp.protocols.tcp-ip Didi <dp(a)tgi-sci.com> wrote:
> On Mar 29, 7:37?am, "JosephKK"<quiettechb...(a)yahoo.com> wrote:
(snip)

>> APR lower level than UDP? ?I don't think so. ?Same
>> level at best, below UDP is MAC and PHY only.

> Uhm, not so sure. Same level as UDP in that they both have the
> Ethernet protocol type set to "internet", perhaps; but the
> data inside a UDP packet are encapsulated into that level,
> whereas the ARP data are purely Ethernet encapsulated.
> This should put it one level lower - at least unofficially?

MAC at layer 2 (ethernet switch level), IP at layer 3,
TCP and UDP at layer 4.

Sometimes I think that ICMP should be layer 4 (as in ping),
other times in layer 3. It does go inside an IP packet.

ARP does not have the IP (X'0800') ethernet type, so it
seems that it should also be layer 3.

-- glen
From: Boudewijn Dijkstra on
Op Mon, 29 Mar 2010 17:10:34 +0200 schreef glen herrmannsfeldt
<gah(a)ugcs.caltech.edu>:
> In comp.protocols.tcp-ip markp <map.nospam(a)f2s.com> wrote:
> (snip, someone wrote)
>
> Some will respond to a ping to the broadcast address, others not.

Some will even respond differently to the subnet broadcast address (e.g.
192.168.0.255) than the global broadcast address (255.255.255.255).


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From: Didi on
On Mar 29, 6:32 pm, "Boudewijn Dijkstra"
<sp4mtr4p.boudew...(a)indes.com> wrote:
> Op Mon, 29 Mar 2010 17:10:34 +0200 schreef glen herrmannsfeldt  
> <g...(a)ugcs.caltech.edu>:
>
> > In comp.protocols.tcp-ip markp <map.nos...(a)f2s.com> wrote:
> > (snip, someone wrote)
>
> > Some will respond to a ping to the broadcast address, others not.
>
> Some will even respond differently to the subnet broadcast address (e.g.  
> 192.168.0.255) than the global broadcast address (255.255.255.255).
>

Hmm, do you still think it is "simple" (just kidding :-)).

The necessity to poll, ping the entire subnet etc. nonsense summarizes
what todays PC programming has become.
Instead of simply sending a single packet to a known destination and
use the single packet reply, why not send a few hundred or, better, a
few
thousand of them (the latter is the case when we would really need it
to
work, of course :-) ), then sift through the replies...

Dimiter

------------------------------------------------------
Dimiter Popoff Transgalactic Instruments

http://www.tgi-sci.com
------------------------------------------------------
http://www.flickr.com/photos/didi_tgi/sets/72157600228621276/

From: Andrew Smallshaw on
On 2010-03-25, Didi <dp(a)tgi-sci.com> wrote:
> I tried today to figure out a simple way to give users of our
> new netmca ( http://tgi-sci.com/tgi/nmcatb.htm ) to locate its
> IP address once it gets one via dhcp when there is no internet
> at the moment (when there is the device posts its IP to our domain
> and customers can see it using a browser).

CDP comes to mind as one option with allows any connected device
to advertise its identity and IP address on the local subnet. I'm
aware that it has at least in theory been superceded by LLDP but
I have no experience of that, and CDP is very simple whereas LLDP
_may_ be more complex. It's primarily a Cisco protocol but it is
documented and clients and viewers are available for Unix and
Windows machines.

--
Andrew Smallshaw
andrews(a)sdf.lonestar.org