Brian Mathis wrote:
On Dec 14, 2007 4:11 PM, Milton Calnek <milton@xxxxxxxxxx> wrote:
Brian wrote:
On Dec 14, 2007, at 3:21 PM, Les Mikesell wrote:
Jerry Geis wrote:
I have a device on my network that is not DHCP and I dont know the IP
address of it
and it has not method of finding it or changing it unless you know
the IP address (setable by browser).
Is there a way on linux, based on MAC address, to get the IP of the
unit?
You accumulate a table of mac<->ip assocations, but only after
communicating with something. arp -a will show the current entries
(which expire fairly quickly). You might ping everything in the
network range, then look for the mac in the arp list.
to ping every address, check out broadcast pings here
http://www.macworld.com/article/53277/2006/10/pingfind.html
(or google other how-to's)
The tool you want is fping. It's available from the rpmforge repository.
fping -ga 192.168.c.d/m
arp -n | grep aa:bb:cc:dd:ee:ff
Now you may have two problems:
1. The unknown device is not in your address space. ie: your net is
192.168.0.0/24 and the ip of the device is 192.168.1.1.
2. Your mask is too large. ie: 192.168.0.0/20 may be too large for you
to scan the entire address space before your arp tables runs out of room.
Good luck.
--
Milton Calnek BSc, A/Slt(Ret.)
You can sacrifice a little bit of speed (this is not parallel) at the
advantage of not having to install another package by doing something
like this (using bash):
for ((i=1; i<=254; i+=1))
do ping -c 5 192.168.1.$i
done
OR
for ((i=1; i<=254; i+=1))
do for ((j=1; j<=254; j+=1))
ping -c 5 192.168.$i.$j
done
done
You sacrifice a lot of speed. To the point where if you do your arp
after all the pings have finished, some of the arp entries at the lower
end will have been deleted based on time when working with one class C.
If you want to do it that way try:
ping -c 3 192.168.$i.$j; arp -n | grep aa:bb:cc:dd:ee:ff
Also seq is much easier to use...
for i in `seq 0 255`; do
You can probably get parallel by adding an "&" to the end of the ping line
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--
Milton Calnek BSc, A/Slt(Ret.)
milton@xxxxxxxxxx
306-717-8737
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