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How to Reserve IP for static client already connected to LAN


I am running a 2003 dhcp server.

I'd like to add a static client to the reservation list. The client is already connected to LAN. When I pick OK, the dialog says: "The specified IP address or hardware address is being used by another client."

I remove the patch cable from the client then tried again to no avail.

What do I need to do?

Thank you,
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5 Solutions
If you go under address leases in DHCP can you find the client there?  If so, you can right-click the client in that list and click add to reservation.
TomislavjSystem AdminCommented:

what is happening when you ping this IP?

then, can you confirm with "arp -a" command that there is no two same MAC addresses?

also, do you see a "BAD ADDRESS" entry in the lease list?

some further reading:

The "Lease duration for DHCP clients" option is set to 0 and some DHCP scope options disappear on a Windows Server 2003-based DHCP server

DHCP Reservations fail with "Specified address is not available" and more!
NVITAuthor Commented:
I reconnected the patch cable for now because I need this client running.

No, it's not in the address leases list.

ping works fine.
arp -a shows the ip by itself.
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TomislavjSystem AdminCommented:
could you copy errors related to desired IP from logs in C:\WINDOWS\System32\Dhcp?
NVITAuthor Commented:

Would these be the *-Mon.log, *-Tue.log, etc. files?
They don't show anything regarding reservations or pertaining to that certain client.

Maybe if I remove the static IP on the client and let dhcp give it an address for now. Then I might be able to reserve it then? I dunno. Just throwing ideas out.

I was wondering if there's a way to have the dhcp server clear out, if any, its record of old reserved IPs. Is there such a thing?
TomislavjSystem AdminCommented:
ok, just to clear it out: on desired client there is static IP defined at this moment?
if yes, then change settings to "obtain from dhcp" and then make a reservation with desired IP, that is correct

server would clear itself based on "lease time", but you can do it manually if you want just by selecting leased (NOT reserverd) addresses and press delete button

TomislavjSystem AdminCommented:
this link might be interesting for some further reading!

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