DHCP Scope Name Change/Synch

Can I assume DHCP scopes imported from a Windows Host are now static objects and hold no relationship to the scope on the Windows side?

1. Imported scope, now lives in Discovered Subnets 

2. Network engineer changes the name of the scope on the Windows side

3. New scope name has not been imported, old scope name still exists in Discovered Subnets

I guess we are expecting a fully automated IPAM synch in the product. Well, the network team is.

Can anyone comment on this?

I just want to give them an idea of how they still need to manage scopes manually in IPAM.

The fact that it did not import the NEW renamed scope is also a question - is there a reason why? I'm not saying that's a bad thing, but I'm trying to understand if there is a GUID or meta data associated with the scope.

The IPAM documentation doesn't mention how scopes are synchronized (or not) unless I didn't see it.


  • I actually opened a ticket regarding a related issue recently. While not the same, it did indicate that the relationship between DHCP Scopes and DNS Zones imported from Windows have a tentative relationship with the objects in IPAM. In my case I found some DNS entries related to IP addresses in IPAM where the zones didn't actually exist on our DNS servers. I realized that the zones had been previously removed on the Windows side, but were retained in IPAM. When I deleted those zones in IPAM, IPAM immediately indicated that it had 'discovered' those same zones and did I want to import them. I tried a similar exercise with some orphaned DHCP scopes, with the same results. Essentially, deleting the entries from IPAM does not actually remove them from the database, so IPAM turns around and 'rediscovers' them.

    I opened a ticket, and was provided some SQL queries I could use to remove the old entries. I pushed back on this, as it seemed a bit ridiculous. The response:

    I understand that deleting scopes from the DHCP server itself creates orphaned scopes in IPAM, and you would like to know if there is an option to synchronize the scopes between the servers and IPAM.

    Unfortunately, by design, we cannot remove the old discovered DHCP scopes in IPAM. For now, we can only manually remove it via the database. 

    I can submit a Feature Request for you since there is no option to do this automatically in IPAM.

    That was all I was able to glean, but it seems apparent that the relationship between DNS/DHCP entries in IPAM and their associated entries on the end servers is somewhat tenuous, and not subject to any sort of on-going synchronization. The statement that this is 'by design' mystifies me; I'd love someone to explain the design decisions around how this all work (or doesn't). 

    I will be delving into this in more detail over the weeks ahead. I haven't been working with IPAM, and inherited an instance that was been allowed to become quite outdated, somewhat do to these restrictions. Cleanup is a bit of a beast, but I'm determined to push to have this all work more seamlessly.

  • You can ask for query to remove orphaned DNS Zones.  It sounds to me that that is something they overlooked rather than "by design".  The Easiest/Fasterr way I can think of is to remove the DHCP server from IPAM and re add them.