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DHCP reservations problem

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y2k1981

Programmer
Aug 2, 2002
773
IE
we've just implemented "static" ip's over the weekend, where we created reservations for each PC. Originally we were using a 0 subnet (ie 10.128.0.*) but then changed to a 1 subnet (ie 10.128.1.*). We deleted all the reservations for the zero subnet, and any leases just in case. Yet now when I ping each PC by host name, some reply with a 10.128.0 ip. There are no reservations in the zero subnet and there are no leases in the zero subnet, so why do these PC's have these IP's? Each one was rebooted after we finished all the reservations also.
 
On the pcs in question you may want to run c:>ipconfig /renew.

Also, if you are using Static IPs, why don't you just assign them on each PC?

LMC
IT/MIS
"Never stop learning.
 
I shouldn't need to do an ipconfig /renew because the reservations were setup on friday when all the PC's were off, and then they were setup on saturday (new rollout). Why don't they appear in the leases either?

Regarding just assigning them to the PC's, beleive me, as far as I'm concerned, that would have been just as easy ... but unfortunately I'm just a mere mortal, nobody listens to me !!
 
Have you looked at the server? Has it been re-booted? Expand the 10.128.1.* scope on the server and see what's inside. Good luck.

Glen A. Johnson
If you're from Northern Illinois/Southern Wisconsin feel free to join the Tek-Tips in Chicago, Illinois Forum.
TTinChicago
Johnson Computers
 
Well, could be WINS or DNS then. Flush all their records and see what happens. My guess is that if you look at your forward lookup zone in DNS for example you may find hosts with the 0 subnet listed there. You can manually change it there to the 1 subnet.
If you integrate your dhcp and dns, this will be done automatically.

Am assumung you have a win2k+ network though.




Claudius (What certifications??)
 
I would advise you look at DNS servers in your network - if your clients register themselves with DNS they will have done this whilst using the Zero Subnet....delete manually all entries pointing at ".0". Delete the scope in DHCP for the ".0".

After this, test on a client machine with a "ipconfig /release" then "ipconfig /renew"...Try now pinging by hostname...The DNS name for the machine should now be mapped to the ".1" range

HTH



MCSA, A+, N+
 
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