DHCP problem

Mikhail Firsov 1,876 Reputation points
2024-02-14T07:57:37.8766667+00:00

Hello! Can anybody tell me why does Windows Server 2012 DHCP service stop giving out IP addresses as soon as the number of available addresses plunges to 4? 01

Why doesn't it just first give out all 100% of addresses before stopping assigning ip addresses? I mean in 100% of cases I see that when there are 4 IPs left in the scope my DHCP service stops allocating addresses to clients and if - for example - my scope consists of 100 addresses only 96 clients can be assigned IPs from the scope... Regards,
Michael

Windows Server 2012
Windows Server 2012
A Microsoft server operating system that supports enterprise-level management, data storage, applications, and communications.
1,532 questions
Windows DHCP
Windows DHCP
Windows: A family of Microsoft operating systems that run across personal computers, tablets, laptops, phones, internet of things devices, self-contained mixed reality headsets, large collaboration screens, and other devices.DHCP: Dynamic Host Configuration Protocol (DHCP). A communications protocol that lets network administrators manage centrally and automate the assignment of Internet Protocol (IP) addresses in an organization's network.
1,023 questions
0 comments

2 answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Karlie Weng 14,331 Reputation points Microsoft Vendor
    2024-02-19T01:47:24.5266667+00:00

    Hello, It is recommended to enable DNS ageing and scavenging. Adjust the lease duration and cleanup interval settings. If problem persists, we may use network capture tool (such as Network Monitor) to monitor DHCP lease process --DORA process (Discover, Offer, Request, Acknowledge) about the new client on network, it would be helpful to identify the details. DHCP Client States in the Lease Process: https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc958935(v=technet.10)?redirectedfrom=MSDN

    ---If the Answer is helpful, please click "Accept Answer" and upvote it.

    0 comments
  2. Mikhail Firsov 1,876 Reputation points
    2024-02-20T14:32:27.49+00:00

    Hello Karlie Weng, Thank you for the reply - I'll take a look at the article! Regarding the number 4: do I get it right that DHCP server does not have any restrictions that would be stopping it from assigning IPs when there're only 4 addresses left? Regards,
    Michael

    0 comments