[c-nsp] Best Ipam software?

[Gustav.Ulander at steria.se]

Hello everyone.
I was a little bit curious as to what people are using to handle and 
manage their ip address spaces? 
I’m primarily looking for a system that can handle multiple instances of 
the same subnet existing. 
We are doing Outsourcing so we have a bunch of customers with overlapping 
Ip address spaces. 
Not a problem technically but a lot of the available ipam solutions seems 
to have a problem with this. 
Would be great to hear how other people have solved this problem. 

/Best regards Gustav