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08-14-2005, 05:41 PM
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#1
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LQ Newbie
Registered: Jan 2005
Posts: 8
Rep:
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How to find IP address of a machine if I know their MAC Address
Hi,
I recently picked up an NCD 88K terminal server, and was wondering how I can figure out the IP address o fhe macine. The MAC address is printed on teh bottom of the machine. Is there any way I can scan my local network to try and find the IP address that corresponds to the MAC address? It would be really nice to just hook up a monitor to the machine, but the female connector is a 26 pin ( 2 rows of 9, 1 row of 8) connector, which I've never seen before. Also when I do an arp -a the mac Address does not show up in my arp table.
thanks,
Jeff
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08-14-2005, 06:23 PM
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#2
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Senior Member
Registered: Oct 2002
Distribution: Slackware
Posts: 1,348
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from a console as root type:
This should give you the mac address and the ip assigned for all machines on the network.
Not sure if this is what you are looking for.
edit:
Actually, on second thought, I'm not certain that's true.
Perhaps it may be useful anyway. I'll check on that and if someone doen't correct me before that I'll correct myself.
Last edited by Franklin; 08-14-2005 at 06:34 PM.
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08-14-2005, 06:41 PM
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#3
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Senior Member
Registered: Oct 2002
Distribution: Slackware
Posts: 1,348
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Yes, I right. It does give the mac address.
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08-14-2005, 08:30 PM
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#4
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Member
Registered: May 2004
Distribution: SuSe v9.3 Professional
Posts: 33
Rep:
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rarp is used to look up ip from mac
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08-15-2005, 12:08 AM
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#5
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Member
Registered: Jun 2005
Location: Pennsylvania
Distribution: Kubuntu
Posts: 197
Rep:
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Of course, if you are like me and your kernel does not support rarp (because it was discontinued in kernel version 2.3), the poor man's lookup is to write a script that:
1) pings every address in the subnet.
2) does an arp -a
3) Finds the line with the correct MAC address and gets the IP address from that line.
Step 1 is really cheating, I guess, and it is probably not a good idea to flooding a large network with pings. However, for a smallish subnet (say with 253 addresses, x.y.z.1 - x.y.z.254), the liberal use of fping may be acceptable. This forces your computer to look up the MAC of each address it pings, and hopefully, it will store them for a few seconds while steps 2 & 3 extract the IP address.
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1 members found this post helpful.
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08-15-2005, 02:08 AM
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#6
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Member
Registered: Jun 2005
Posts: 542
Rep:
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It's easier to ping the subnet's broadcast address with "ping -b" then ^C and then look at "arp -a"
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08-15-2005, 02:32 AM
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#7
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LQ Guru
Registered: Nov 2004
Location: San Jose, CA
Distribution: Debian, Arch
Posts: 8,507
Rep:
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Rather than ^C it, just do 'ping -b -c1 192.168.1.0', but replace the IP with that of your network
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08-15-2005, 09:33 AM
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#8
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LQ Newbie
Registered: Nov 2004
Location: Freising, Germany
Distribution: Fedora 3
Posts: 6
Rep:
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set up a tcpdump with "ether host aa:bb:cc:dd:ee:ff" option
Huppert
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08-15-2005, 09:48 AM
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#9
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Member
Registered: Aug 2005
Location: NY,USA
Distribution: Debian, Gentoo, Ubuntu
Posts: 103
Rep:
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i believe that arp -na will only give you the IP and mac of computers that are connected to "this" computer. I ran it on one of my boxes and it only showed 3: the router, and two computers which are connected with mounted shares. There are about 8 other computers on my network which didn't show up (and are all not connected)
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08-15-2005, 10:45 AM
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#10
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Member
Registered: May 2004
Location: Cornwall, UK
Distribution: Ubuntu 8.04
Posts: 464
Rep:
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Hook the unit up to a PC with a cross over ethernet cable. Then run Ethereal and see if you can collect any packets. Ethereal should display the IP address along with any other info.
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08-15-2005, 10:52 AM
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#11
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LQ Newbie
Registered: Jan 2005
Posts: 8
Original Poster
Rep:
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collecting packets with ethereal
thanks for all the replies. I think connecting to iit with a crossover cable and collecting packets with ethereal is my only option because I think the device has a static IP and I have no idea what it might be. So if I set up my linux machine with an ip of 192.168.0.2 and connect to the terminal device with a crossover, will I still be able to pick up packets if the other device is on another subnet?(im at work, or i would just try it)
thanks,
Jeff
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08-15-2005, 11:01 AM
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#12
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Member
Registered: May 2005
Location: Greece
Posts: 441
Rep:
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Maybe i am wrong, but how about "arping" ?
In my box it works ok:
root@box:~# arping -i eth1 00:E0:29:XX:YY:ZZ
ARPING 00:E0:29:XX:YY:ZZ
60 bytes from 192.168.0.AAA (00:e0:29:XX:YY:ZZ): icmp_seq=0 time=47.922 usec
60 bytes from 192.168.0.AAA (00:e0:29:XX:YY:ZZ): icmp_seq=1 time=44.823 usec
60 bytes from 192.168.0.AAA (00:e0:29:XX:YY:ZZ): icmp_seq=2 time=84.877 usec
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09-12-2005, 09:07 AM
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#13
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LQ Newbie
Registered: Sep 2005
Distribution: Slackware
Posts: 2
Rep:
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What version of arping are you running? The version that comes with the current iputils package can only ping IP addresses.
/GSt
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09-12-2005, 11:21 AM
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#14
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LQ Newbie
Registered: Sep 2005
Distribution: Slackware
Posts: 2
Rep:
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Problem found: There are two versions of arping. One by Alexey Kuznetsov that pings IP addresses and one by Thomas Habets that pings MAC addresses.
Why on earth give them the same name?
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