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On Thursday 26 May 2011 17:24:05 Florian Philipp wrote: |
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> Am 25.05.2011 21:45, schrieb Harry Putnam: |
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> > There must be a number of people who post here that have had to do |
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> > this problem. |
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> > |
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> > Discover the addresses of computers on a home network that have |
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> > connected by way of DHCP. For example: Several wireless connections. |
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> > |
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> > I've used static IPS for around 10 yrs, always seemed handier for |
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> > things like ssh between home lan computers. |
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> > |
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> > But recently started using DHCP for wireless connections. It must be |
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> > such a popular method for some reason. |
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> > |
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> > But when you do it that way, and say want to VNC or ssh or the like to |
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> > something connected by a dhcp serving WAP then how do you find the |
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> > address? |
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> > |
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> > That is, besides something like accessing the WAP and checking the IPs |
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> > connected to it. |
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> > |
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> > Is there some quick and sure way to discover any IPs on the home lan? |
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> > |
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> > Some kind of mapper tool? |
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> |
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> While I personally prefer a combined DHCP+DNS server like dnsmasq, you |
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> can also take a look at the whole Zeroconf/MDNS/Avahi/Bonjour stack. |
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> |
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> I'm not really sure if you can configure common devices and Linux PCs to |
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> use the DNS server for internet addresses and MDNS for local ones. In |
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> theory, it should be possible since you can distinguish them (local |
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> addresses should not be fully qualified _or_ have the domain .local). |
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> |
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> net-misc/mDNSResponder, sys-auth/nss-mdns and net-dns/avahi are probably |
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> good starting points. |
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|
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netdiscover seems to do exactly what the OP asked for, although I have used |
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arping and a couple of scripts I found on the net and modified them. |
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|
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The first looks like this: |
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============================= |
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#!/usr/bin/env bash |
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|
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quit_on_found=0 |
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packet_count=2 |
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subnet="" |
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verbose="-q" |
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|
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usage() |
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{ |
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cat << EOF |
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find_ip 1.0 Robin Wood (dninja@×××××.com) (www.digininja.org) |
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|
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Find used and unused IPs on a network you don't haven an IP address on |
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|
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usage: $0 options |
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|
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OPTIONS: |
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-h Show this message |
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-c <packet count> The number of ping packets to send, default 2 |
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-s <subnet> First 3 parts of the subnet to test, default |
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192.168.0 |
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-q Quit when found first free address, default keep |
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going |
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-v Verbose |
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|
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EOF |
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} |
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|
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have_arping=`which arping` |
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|
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if [[ "$have_arping" == "" ]] |
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then |
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cat << EOF |
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usage: $0 options |
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|
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You must have arping installed and in the current path for this scanner to |
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work |
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EOF |
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exit 1 |
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fi |
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|
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while getopts ":hvs:qc:" flag |
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do |
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case $flag in |
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h) |
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usage |
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exit 1 |
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;; |
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c) |
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packet_count=$OPTARG |
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;; |
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q) |
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quit_on_found=1 |
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;; |
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s) |
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subnet=$OPTARG |
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;; |
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v) |
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verbose="" |
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;; |
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?) |
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usage |
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exit 1 |
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;; |
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esac |
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done |
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|
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if [[ "$subnet" == "" ]] |
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then |
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cat << EOF |
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usage: $0 options |
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|
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You must provide a subnet |
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EOF |
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exit 1 |
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fi |
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|
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if [[ "$verbose" == "" ]] |
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then |
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if [[ $quit_on_found == 1 ]] |
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then |
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echo "Quiting when found a free address" |
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fi |
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echo "Testing subnet $subnet.0/24" |
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echo "Sending $packet_count packets per IP" |
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fi |
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|
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for i in {1..254} |
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do |
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IP=$subnet.$i |
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arping $verbose -c $packet_count $IP |
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result=$? |
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if [[ $result == 0 ]] |
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then |
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echo "$IP Used" |
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else |
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echo "$IP Free" |
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if [[ $quit_on_found == 1 ]] |
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then |
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exit |
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fi |
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fi |
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done |
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============================= |
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|
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Google for "find_ip.sh" |
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|
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The other which I can't find at the moment prints out the MAC address of each |
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IP address that is in use. Alternatively, run the above script with the -v |
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option and then scroll back to look at the MAC addresses. |
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|
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Of course, I was using this before I knew that netdiscover existed - thanks |
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for sharing! |
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-- |
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Regards, |
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Mick |