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JanusBarinan-8508 avatar image
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JanusBarinan-8508 asked Kcmjr-4204 answered

Active vs Inactive IP reservation

What is the difference between an Active IP reservation vs an Inactive IP reservation?
How is it determined?

windows-dhcp-dns
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GloriaGu-MSFT avatar image
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GloriaGu-MSFT answered JanusBarinan-8508 commented

Hi,

Thank you for posting in Q&A!

After my test , when the client release the IP(I use command"ipconfig/ release"), the reservation lease will become inactive.

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Hope you have a nice day : )
Gloria
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I did also your test and it worked. Releasing the IP lease makes it inactive.

But if the workstation is disconnected from the network for a long time will it's reserved IP become inactive?

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Hi,
According to my test, I set the lease time to 5 mins and disconnect the client. In this situation, the reservation lease will still remain active.

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So once it leases the reserve ip address it remains active unless otherwise the user will initiate a release.

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GloriaGu-MSFT avatar image
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GloriaGu-MSFT answered GloriaGu-MSFT commented

@JanusBarinan-8508 Hi,

Thank you for posting in Q&A!

The active/inactive indicates whether your DHCP server has handed out the address or not.

In order to get the reservations in the DHCP server to be shown as Active, the machines you've assigned reservations for need to use DHCP for ip address assignment (not static ip).

On DHCP client, you can run 'ipconfig /release' and 'ipconfig /renew', after a refresh in the DHCP console, they should show up as Active if all is configured OK.


Hope you have a nice day : )
Gloria
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So the client will send out a dhcp request for an IP then the DHCP server will give out the reserved ip for that client making it active.
So if the client will not send out a dhcp request to the dhcp server that reserved IP will be inactive?

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Yes, since the reservation IP lease is related to the client's MAC address. If the client send out a dhcp request then the DHCP server will give out the reserved ip for that client making it active.
if the client will not send out a dhcp request to the dhcp server that reserved IP will be inactive? - Yes.

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Once active will it remain active forever?

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Kcmjr-4204 avatar image
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Kcmjr-4204 answered

I inherited an old Windows 2008 DHCP server. Most of the scopes had been migrated to a newer domain but a few are still being used. The reservations on the old server have remained showing as "Active" months after the devices no longer use them. I think this is some sort of bug in the older DHCP implementation. It's extremely frustrating but the fix is to get all clients onto a new version of DHCP server at this point. I've only observed this on older versions of DHCP. One would think that even reservation statuses should go inactive if the client hadn't requested a renewal at some point but that doesn't seem to be the case.

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