DHCP - Addresses marked as used but they are not being used

My dhcp on a windows server 2000 box with spk 4 statest that I have 228
addresses available, but it says I am using 218 with 10 left but I only have
a total of 181 in leases, reservations, and exceptions. I have addresses out
there that are available because if you ping them they come up timed out.
They do not show as being used in leases, reservations or I have not put them
as an exception. I have looked in Knowledge Issues but I cannot find any
reason why this would be happening. I am adding 8 new computers so I will be
down to 2 and it will be hard to function with just 2 unless I can get this
issue figured out and use the other 45 that i should have available.

Thanks!!

Hi,

ping is often not the best way to determine if IP address is in used or not.
E.g. if user have enabled personal firewall -- you might not get ICMP (ping)
reply, but the computer actually does have that IP address in use.
What I usually do is also look at MAC address cache. If e.g. I don't get
ping reply I will run

arp -a

and see if the computer's IP address and MAC address will show up in the
cache. If it does and MAC address is valid then the computer on the network
have that IP address in use.

--
Mike
Microsoft MVP - Windows Security

"FNBTech" <(E-Mail Removed)> wrote in message
news:42277551-3181-4CEE-93E6-(E-Mail Removed)...
> My dhcp on a windows server 2000 box with spk 4 statest that I have 228
> addresses available, but it says I am using 218 with 10 left but I only
> have
> a total of 181 in leases, reservations, and exceptions. I have addresses
> out
> there that are available because if you ping them they come up timed out.
> They do not show as being used in leases, reservations or I have not put
> them
> as an exception. I have looked in Knowledge Issues but I cannot find any
> reason why this would be happening. I am adding 8 new computers so I will
> be
> down to 2 and it will be hard to function with just 2 unless I can get
> this
> issue figured out and use the other 45 that i should have available.
>
> Thanks!!

Yes, I am aware of all of that. All the addresses that get a reply back when
pinged add up to all the computer on my network. It is reading the ones that
state timed out when pinged to the total value also. I have 181 computers on
my network. I have 225 available addresses but dhcp says I am using 225 when
I only have a total of 181 in reservation and leases. All other ones are not
being used at all.
I do not have windows firewall activated on winxpspk2 machines. My question
is why would dhcp record all my addresses as being used when 1/4 of them are
not being used at all.

"Miha Pihler [MVP]" wrote:

> Hi,
>
> ping is often not the best way to determine if IP address is in used or not.
> E.g. if user have enabled personal firewall -- you might not get ICMP (ping)
> reply, but the computer actually does have that IP address in use.
> What I usually do is also look at MAC address cache. If e.g. I don't get
> ping reply I will run
>
> arp -a
>
> and see if the computer's IP address and MAC address will show up in the
> cache. If it does and MAC address is valid then the computer on the network
> have that IP address in use.
>
> --
> Mike
> Microsoft MVP - Windows Security
>
> "FNBTech" <(E-Mail Removed)> wrote in message
> news:42277551-3181-4CEE-93E6-(E-Mail Removed)...
> > My dhcp on a windows server 2000 box with spk 4 statest that I have 228
> > addresses available, but it says I am using 218 with 10 left but I only
> > have
> > a total of 181 in leases, reservations, and exceptions. I have addresses
> > out
> > there that are available because if you ping them they come up timed out.
> > They do not show as being used in leases, reservations or I have not put
> > them
> > as an exception. I have looked in Knowledge Issues but I cannot find any
> > reason why this would be happening. I am adding 8 new computers so I will
> > be
> > down to 2 and it will be hard to function with just 2 unless I can get
> > this
> > issue figured out and use the other 45 that i should have available.
> >
> > Thanks!!
>
>
>