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DHCP lease not listed in leases table RRS feed

  • Question

  • We've been running Windows DHCP for a while and have not ecountered any issues until today's weirdness. We had a printer that was set up for DHCP get put online before we were able to create a DHCP reservation for it. So, it got an IP address that we didn't want. 

    I was made aware of the issue 2 days later, and the only info that was handed to me was the IP address. No big deal, I fired up the DHCP administrative tools, added our 2 DHCP servers, and went to the leases table to look up the IP address so that I could get the devices MAC address that I would later use to create the DHCP reservation. Now for the wierdness, the lease wasn't there. It wasn't in either of our DHCP servers leases table. So, I figured, that the printer wasn't connected to the network anymore. I tried to ping the IP that I was given and got a reply. I then went to the printers web interface, and saw that it was completely functional. I figured maybe one of our endpoint techs had set it up statically. I was surprised to see that it was configured for DHCP, and the lease had 6 days left (we use 8 day leases).

    Has anyone else seen a situation like this? Where an IP address was dished out via DHCP, but the entry is not located in the leases table? Do you have any troubleshooting suggestions for me?

    I ended up grabbing the MAC address from the printer's web interface, and was able to set up the DHCP reservation without issue. So, everything is working at the moment. I just want to know why that lease wasn't listed in the table.

    *EDIT*

    I should also add that there isn't anything funky in the logs regarding this MAC address. I searched for the MAC address within the logs on both servers and only see Renewal entries (code 11) and failover entries "Packet dropped because of Client ID hash mismatch or standby server." (code 36).

    Wednesday, July 27, 2016 3:38 PM

All replies

  • Hi,

    Please check the DHCP aduit log,is there anything related?Have you tried to reconfigure the DHCP settings on printer?Maybe some unusual situation.Of course restart the DHCP service and printer together.If you still get this issue,considering the other's working fine with DHCP,it could just this printer is not fit with Windows DHCP server,you may connect to the manufacturer for further assistant.

    ________________________________________
    Best Regards,
    Cartman
    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Thursday, July 28, 2016 1:45 AM
  • @cartman

    Are you talking about logs other than C:\Windows\System32\DHCP\* ? Cause I checked in there, as you can see in the edit of my post.

    Also, as I wrote in my post, everything is working fine with the printer. I am just curious to see if anyone has seen this behavior before and what I could look for to see if anything is a amiss.

    Thursday, July 28, 2016 12:46 PM
  • Hi,

    >>I am just curious to see if anyone has seen this behavior before and what I could look for to see if anything is a amiss.

    It is more like an unexpect accident.I will keep an eye on this,if there is something related,I will come back and update.

    ________________________________________
    Best Regards,
    Cartman
    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Friday, July 29, 2016 2:44 AM
  • If you are using 2012 or better as your DHCP server, fire up PowerShell on that box and use the Export-DhcpServer command to define the scope the IP belongs to and where to put the output.

    Example:  Export-DhcpServer -File c:\dhcpexport\export.xml -ScopeId [scopeId]

    After you do that, use Notepad or whatever you like to look at the XML output.  Specifically, look at the sections between the <Leases> and </Leases> tags.  You'll probably find the lease there and you can remove it by deleting the lines for that lease marked <Lease> and <\Lease>.  If you find that IP lease and remove it, use Import-DhcpServer to pull that scope back in and be sure to set the options to overwrite the current scope.

    This can happen if a lease was made in a scope, but later on the scope was changed to possibly exclude portions of the range and this lease now exists outside the allowed ranges.  It could also come from an unreconciled DHCP database.  That can be fixed using Repair-DhcpServerv4IPRecord.  Easiest way to use that is like this:

    Get-DhcpServerv4Scope | Repair-DhcpServerv4IPRecord -Force

    Run that a few times until it comes up blank.  If it never blanks out for a particular scope or group of scopes, Export those, clean out the bad records, and re-import, being sure to set Import-DhcpServer to overwrite.

    • Proposed as answer by GPF Friday, August 19, 2016 2:52 PM
    Thursday, August 11, 2016 5:59 PM