Hello,

How can I check free IP address in linux server. as we can see IP address through command ifconfig , but I want to check free IP address which are assigned to my server.

Please can anybody tell me the command as i have searched on internet and was not able to find the command

Thanks.........

Erm?

This is something you have to ask your server's ISP, if you try taking any available IPs within the same network you could very well land yourself in trouble for stealing IPs that do not belong to you. And trust me, I am a datacenter technician, such things are not taken lightly at all.

If you have a pool of IP address assigned to you, you can find that IP address range by looking at the IP Address and Subnet mask.

Hence if your server IP address is 203.124.220.1/255.255.255.248 then you have pool of IP address 203.124.220.0 - 203.124.220.7 . To find out if they've been assigned to some other machines just ping each one of them and see if you get a reply - This of course will give false positives if you have firewall blocking ICMP protocol.

Not a good way to do it, where I work, we generally assign customers a single IP in a 255.255.255.xxx range, the IPs themselves are actually port and mac address locked for our dedicated servers so customers can't steal IPs from other dedicated servers but just because the 4th octet it isn't a 0 doesn't mean this is a pool for the customer. Also a server ISP are very unlikely to assign you more then 1 or 2 IPs unless you request more, and if they are doing it properly not until the IP usage has been justified in accordance to the IP regulatory body for the region. Like ARIN for North American or RIPE for Europe.

I have experience with this and know that if an ISP didn't do this, they could soon find out one of their rivals or a disgruntled customer could then report them to said regulatory body what could lead to IP auditing. Never had to experienec and audit thankfully but as one of the people who have this role as apart of their job, I am mindful about apathy in assigning IPs to the customers.

In this case you should definetly talk to your Network Administrator as using a random hit and trial method of checking and assigning free ip address can cause ip conflict in future.