IP Address Tracking

[stebbo]

Hi All,

I'm looking to formalise my IP address allocation and tracking policies and was thinking that the nagios system would be a perfect place to store and track all my IP addresses. Is there any such feature within Nagios?

If no, what do people mostly use?

Cheers,
Chris.

[yancy]

stebbo,

Nagios does not store IP address so to say (only IP address it monitors). Can you explain better how IP address tracking would work? Are you using static IP address instead of DHCP?


-Yancy

[stebbo]

Hi Yancy,

we use a /20 range that is mostly allocated via dhcp but we have two class-C ranges within the larger range which we reserve for static IP addresses, servers, printers etc.

Historically, the IT Department has used a text document to allocate the static ip addresses, which seems to have worked well when adding servers, but not so well when retiring or changing them. So now my two class-C ranges appear to be almost full when in reality they're not.

So I'm looking for something that will combine a manual allocation practice with a periodic scan to ensure that retired servers are removed and the address space allocation is accurate. I actually think I might be able to return one of the -C ranges back to the dhcp pool, particularly with some judicious use of dhcp address reservations.

So I suppose I'm asking is if everyone is happy using a spreadsheet / text document to record/manage their static address allocations or if there's some smarter software out there. (I've seen one, but at $2000 that's so far away from reality that it's not worth contemplating).

I thought Nagios would be perfect as I could enter the static ip address ranges, and Nagios could periodically go out and correlate those that are used/free with a quick ping or two - especially given that I don't need to monitor all of these devices.

Cheers,
Chris.

[yancy]

stebbo,

Thanks for providing some clarification.

The first thing that comes to mind is Nmap which can be used to scan a network and find what devices are active in a given range of IP address. Nmap will provide a lot of detail and even identify what type of devices exist at a given IP address (with some degree of error). The autodiscovery wizard included with Nagiosxi uses Nmap to discover what hosts are available for monitoring.

A solution could be to automate an autodiscovery job of the given range, and then add or remove hosts based on what is discovered in the class C range. You could group these in a hostgroup and in that way have a live monitoring view of what devices exist in a given subnet.

That being said, we may need to extend some of the functionality of our autodiscovery wizard to make this work. Or you could implement a similar solution yourself with Nmap.

Thoughts?

-Yancy

[stebbo]

Hi Yancy,

I like your idea of a hostgroup for a given subnet range that could be automatically scanned at regular intervals and then the user could be notified when new hosts are found or old hosts have not responded for a given time. If there was the ability to make comments about each IP address which responded then that would be ideal for me.

I shall look into nmap. The thing I like about including it into nagios is that I have my nagios screens live all the time and therefore new or old hosts would be identified very quickly.

Thanks for the responses.

Cheers,
Chris.

[yancy]

stebbo,

I'll look into how we can make this happen with the autodiscovery wizard. I'm going to close the issue but feel free to pm me for an update.

-Yancy