IP Address Manager

October 25, 2005 11:38 AM

IPfilter:Does anyone know of a good FREE program to manage your ip address with? As in which ones are marked available or used. Something like Enterprise IP -address manager http://www.enterpriseip.net/ but free and for Windows.
posted by flipmiester99 to technology (10 comments total)

sorry...I meant "LAN addresses" instead of "address"
posted by flipmiester99 at 11:46 AM on October 25, 2005

nmap -sP 192.168.1.0/24 ?
posted by shepd at 11:49 AM on October 25, 2005

A DHCP server with address reservations?
posted by internal at 11:52 AM on October 25, 2005

I need something that multiple people can look at and have access to. We are constantly having boxes change addresses so im looking for something that someone can update. I can use excel but id rather not. Any Ideas?
posted by flipmiester99 at 11:58 AM on October 25, 2005

We are constantly having boxes change addresses so im looking for something that someone can update.

Then why not statically define the IP addresses assigned by DHCP by hardware address. (This is what internal is talking about).

ie: Your network card has MAC FF:FF:AA:22:56:89, you set up your DHCP server to always assign IP address 192.168.1.55 to that MAC address. Do that for all the rest of them and you're good to go for the life of the item. All MAC addresses on all cards sold by reliable vendors are reserved from the MAC address database and will ALWAYS be unique. Really terrible vendors will re-use MAC addresses, so if you have thousand of machines you might get a collision. Not likely, though.

The MAC address on a device will not change, ever, unless someone mucks with it (which they can if they desire). Of course if that happens you should probably consider not giving them a network cable. :^D

The only time odd IPs will come up then is when someone plugs in a new device. If it's only there for a short while, clearly no need to define a static IP for it. If not, well, there you go.

Only the worst of DHCP servers don't have the option to statically define IPs this way. Even ancient DHCP predecessor BOOTP supported this.
posted by shepd at 12:15 PM on October 25, 2005

DHCP, you can even do static DHCP with a lot of the $5AR NAT appliance/routers.. i.e. hook it up and just use it for a DHCP appliance. this is exactly why it exists.
posted by kcm at 12:21 PM on October 25, 2005

We have the same problem, but no solution. The problem is roaming clients and laptops and such that attach both wired and wirelessly, and possibly on separate VLANs. Then there are Virtual Machines running in VMWare sessions, and the like.

Then, there are things on the network that do not DHCP well - such as printers, switches, wireless APs, and other random stuff, cameras. You can enter reservations in the DHCP server, but it doesn't provide an easy way to lookup what is using what, and why.

And how do I know when our network is coming close to the limit on the subnet, such that I need to add additional subnets?

This is a valid request, and there has to be something out there.
posted by stovenator at 2:12 PM on October 25, 2005

We have the same problem, but no solution. The problem is roaming clients and laptops and such that attach both wired and wirelessly, and possibly on separate VLANs. Then there are Virtual Machines running in VMWare sessions, and the like.

Well, while you might not be able to control the basic DHCP address handed out without pulling your hair to shreds, you can simply implement something like PPTP which will hand out only one static IP address assigned to one username/password combo (you can have more than one combo and a new static IP each one, obviously).

You make the IP handed out by DHCP on a useless network that can only access the PPTP server so any "abuse" there is negligible. Access to your real network is done by VPN via PPTP.

It's how I implemented truly secure wireless access at work and home. If you're worried about the quality of PPTP you can try IPSec, but that's too much pain for me. :^D

[Originally, this idea was going to be to allow customers to get free advertising supported HTTP access on wireless, and they could purchase extra full access time (a PPTP login) at a reasonable fee. It wasn't implemented due to lack of interest, sadly. Yeah, we are beside a coffee shop with no wireless. Ho hum.]

You can enter reservations in the DHCP server, but it doesn't provide an easy way to lookup what is using what, and why.

Run the nmap command above to see which of your addresses are in use by non-rogue items. Rogue computers obviously won't respond to ping scans. The why, well... you should know *why* the item you're hooking up requires an IP! Heh...

And how do I know when our network is coming close to the limit on the subnet, such that I need to add additional subnets?

Check the logs! Also, again, run the nmap command above (modified for your subnet, of course) to see how many IPs are still available for your subnet.
posted by shepd at 2:59 PM on October 25, 2005

I like netscan.
posted by hoborg at 4:46 PM on October 25, 2005

Angry IP Scanner also does what you want.
posted by kaefer at 8:16 PM on October 25, 2005