Available IPs

[TheCrazyHacker]

I wrote this program because at my job, I often have to move printers and computers back and forth between static IP addresses and DHCP assigned. I got tired of pinging random IP addresses until I found one that was available. So, I wrote this little program to find and create a list of available ones.

http://www.fusionsolid.com/Projects/Ava ... e_IPs.html

[dany]

Nice. There are other apps that do the same, but still. nice.

[Leif]

There are other apps that do the same

Such as?

[dany]

Angry IP Scanner or SoftPerfect Network Scanner and quite likely others as well. They can all scan a network and list IP's that are available.
The real question is of course: is this IP really available or is it just a machine that's currently turned off? Since you mention static IP's in your first post, I'm assuming your app is really dedicated to answering that question, whereas the apps above only ping all IP's in a given range.

A small question though: Why can I only scan 1-253, why the exclusion of 254-255?

[TheCrazyHacker]

The real question is of course: is this IP really available or is it just a machine that's currently turned off?

No, it's not that intelligent. It only uses pings to determine if an IP address is used.

A small question though: Why can I only scan 1-253, why the exclusion of 254-255?

The 255 octet is not a valid IP address. It is used for broadcast messages (http://en.wikipedia.org/wiki/Broadcast_address). And with this scanner, you can scan up to 254, which is the highest octet available. I set the range so that you can scan up to 1 less than the higher value, thus if you want to scan up to 254, you have to enter a range of 1-253 to the max of 254. This scenario makes sense to me.

[dany]

This scenario makes sense to me.

If you put it like that, yea makes total sense. The other apps do allow pinging the full range up to 255, that's why I asked.

About the range: just noticed that the second box goes up to 254, the first only to 253. Missed that.