If you manage some servers you need to document, which server has got which ip address. I have written an small webapp for that stuff. You can create companies, networks and servers.
One server could have one operation system, one server type (like hardware or virtual) and the mac/ip addresses. For every operation system you can save an preseed configuration for debian installation.
Some screenshots of the app:





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Update:
It works like the extlookup, but not with files - it does an database lookup.
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Planed features:
- authentication
- connect virtual servers to hardware nodes
- ...