Typically DHCP Leases show an computer icon with a clock on it, this is normal and good. However, if you see a Pen on that computer instead of the clock, it is telling you that DHCP has some pending writes to DNS. This not good. In my case it meant that my DHCP scope had bled into a new class C range which was not setup in REVERSE DNS. This was a super easy fix.
The above icon indicates “Active lease, DNS dynamic update pending. This address is not available for lease by the DHCP server.” DHCP is configured to “Automatically update DHCP client information in DNS” and “Update DNS only if DHCP client requests”.
To correct this issue do the following:
- Create a reverse lookup zone in DNS for the subnet of the affected leases.
- Verify that both the Forward Lookup Zone and Reverse Lookup Zone allow Dynamic Updates (either Secure or Non-Secure).
- Delete the entry for the client machine from the Address Leases on the DHCP Server.
- Delete the Host record for the client machine from the DNS Server.
- Release the IP address of the client machine using IPCONFIG /RELEASE.
- Reboot the client machine.
Now the Address Lease should show the usual icon (computer icon without a pen).