network scanning

[Hari Prasad S R]

Hi guys,

is there any tool to scan network for free ipaddress in a particular range of ipaddress in hpux 11.00

[Mel Burslan]

Well this is not a tool but you can use this ping approach.

determine the decimal numbers for the start & end address of the range you want to scan as follows

IP address=a.b.c.d

decimal representation
(a*256*256*256)+(b*256*256)+(c*256)+d
[do this for bots start and end of your range ip addresses]

START_ADDR=
END_ADDR=

IP=${START_ADDR}
while [ ${IP} -le ${END_ADDR} ]
do
loss=`ping ${IP} -c 3 |grep "packets transmitted"| cut -d, -f3| cut -d% -f1|cut -d" " -f2`
if [ ${loss} -eq 100 ]
then
echo ${IP} >> /tmp/avaiable_IPs
else
echo ${IP} >> /tmp/inuse_IPs
fi
let IP=$IP+1
done

when you are done, you will have the IP addresses in decimal form in the
/tmp/avaiable_IPs file. You need to do the IP address conversion in the reverse manner to determine the addresses in a.b.c.d form

Keep in mind that, an IP address not responding at one time does not necessarily mean that it is available guaranteed. The workstation with that IP address may have an owner who failed to turn on the computer at the time you did the scan. So, if I were you I would do this scan at different times of the day for a couple of weeks and combine all the output at the end for a better chance of getting it right.

Hope this helps

[Mel Burslan]

sorry there was a typo in the script

the correct version of the following ping statement should be as follows:

loss=`ping ${IP} -n 3 |grep "packets transmitted"| cut -d, -f3| cut -d% -f1|cut -d" " -f2`

the packet count is is -n not -c as I have put it down on my posting above. And although it broke down into two lines, it actually is on a single line.

[Bill Hassell]

This is not a good idea to locate a free address (ping to find unresponsive addresses). If a particular printer or computer is offline, the ping will fail and if you use that address, your system will be clobbered when the printer or computer is turned back on. This is an ideal solution for a DHCP server. Otherwise, you'll need to create a spreadsheet of machines and IP addresses and make sure no one violates the rules about getting an official IP address.

[Hari Prasad S R]

Hi Bill,

I tryed your ping script but i am getting a problem for the starting ipaddress itself i have calculated for the ipaddress (32.85.128.230) and i got 542474470 this itself it is giving error as

ping[7]: [542474470: not found

thanks

[Yogeeraj_1]

hi,

you may try to run the free windows-based utility called "Angry IP scanner"

http://www.securizare4u.go.ro/download/ipscan.exe

hope this helps!
regards
yogeeraj

[Hari Prasad S R]

Hi yogeeraj,

Actually i have set of static ips assigned to unix workstations(which includes sun solaris and HP -UX), in that how to find assigned ipaddress.
i am looking for a tool where it should tell me what are used ips with platforms.

thanks

[RAC_1]

Pinging range ip address is not a good idea as Bill pointed. Yuo can do the same thing by pinging the broadcast address on the network. That will ping all ip addresses on that network.

But the correct procedure, should be contacting your network administrator and ask him for free ip address.

Anil