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does anybody of you use some tool to managed IP address space in a classless environment for a bigger organization?

Willi have you seen Nigel Titley's 'tree' programme - it might be what you want. Find it at

ftp://ftp.bt.net/networking/tools/tree/tree-2.1.5.tar.Z

Cheers.

Mike

Many thanks to all, that answered. I will have a look at Tree. Regards, Willi