How can you poll multiple isolated sites that are in same IP space?

Yes type for seach range.

Now you can to monitor the sites external link.

I'll be interested in seeing how someone recommends accomplishing this.

If there were something unique about each network, such that you could write static routes to send your NPM polling to unique 32-bit addresses, or sub-ranges of the original 24-bit range, I could imaging how to do it.

But suppose the two different 10.0.0.0/24 subnets have a device at 10.0.0.10/24 that you want to monitor with NPM.  You'd need to be able to ping each one separately, and your routing won't know how to do it.  Without a separate routing solution for each one, I don't see how it could be accomplished with a single instance of NPM.

Can you ping each one separately from the same NPM instance?  I don't see how, and without that, NPM won't be able to poll / monitor / discover two devices on different subnets with the same address.

`With the same ip it will not do.

I had not paid attention to it.

You can use NAT on each end of the link so that the NPM appears with a local IP on each  remote site and have each remote site appear with a local IP on the NPM network.

True.  But ugly.  Still, an accurate answer if you can get it to route the way it's needed.  Good thinking.

Could try dropping a poller into each subnet - but I don't know how npm would handle it. Route NPM discovery into one subnet, then after the discovery re-route to the other subnet.  Seems like a simpler solution would be just to re-subnet one of the 10.0.0.0/24s into 10.1.0.0/24.

Thanks everyone.  Yes, NAT is the obvious solution but won't be wont scale well if you start talking a large amount of IP's to NAT.  I was hoping someone had some trick with IP+SNMP STRING or IP+Customer property, or something else.  But yes, it does come down to polling the IP which you can't have duplicates.  

Yea, NAT would do it - but it just seems so superfluous to me.  It's only 254 max hosts, seems like it would be easier to re-ip, but either way it'll work.

Re-IP'ing is definitely the way to go, as long as it's just one /24.  Networks require unique address spaces--no overlaps and duplicates are allowed.

Unless you are running vrf-lite or something with multiple routing tables... and nating it through... but whaaaaat a mess.