Windows Autoconfiguration IP Address

[Rod]

I am using a router to assign static IP addresses to specific MAC
addresses (PC's and VOIP phones) as a security measure. Physical
security of the equipment is not very reliable in our office building.

Some of the PC's latched onto their assigned I.P. addresses, but two
did not. The router logged them as "spoofing" from inside the LAN.

When I enter an "ipconfig /all" on the two offenders, they report an
"Autoconfiguration IP Address". I do not know how/why this occurs.

I went into the network properties and manually entered the IP values
(192.168.0.x). It is as though the router cannot authenticate them,
unless I key in the matching IP address. The other PC's do not need
this; the MAC address entered in the router is enough.

All of the machines are Windows XP. Is there a setting somewhere that
I have not found?

I want to minimize the hassle for mobile users that will need to
connect to more than one network.

rsquared

 

[Jack \(MVP-Networking\).]

Hi
If your are referring to an Entry Level Router.
Assigning Static IP (in a Router that allows it) means that the same
computer with the same MAC address would be always assigned with the same
IP, it does not change the actual TCP/IP settings in the computer.
If the address is assigned by the Router is Static, or Dynamic, the
Computer's settings still remain on Auto Obtain.
If you actually assign a static IP in the computer's TCP/IP menus, you do
not have to do any thing in the Router.
However, The address has to be an address out of the DHCP server of the
Router.
I.e. if the DHCP is set to assign 50 IP from 192.168.x.1, the static IP in
the computer should be above 192.168.x.50.
Jack (MVP-Networking).

 

[Rod]

Hi
If your are referring to an Entry Level Router.
Assigning Static IP (in a Router that allows it) means that the same
computer with the same MAC address would be always assigned with the same
IP, it does not change the actual TCP/IP settings in the computer.
If the address is assigned by the Router is Static, or Dynamic, the
Computer's settings still remain on Auto Obtain.
If you actually assign a static IP in the computer's TCP/IP menus, you do
not have to do any thing in the Router.
However, The address has to be an address out of the DHCP server of the
Router.
I.e. if the DHCP is set to assign 50 IP from 192.168.x.1, the static IP in
the computer should be above 192.168.x.50.
Jack (MVP-Networking).












- Show quoted text -

I think I understand:

1. Leave the router's DHCP on.
2. Configure the router to reserve IPs for specific (authorized) MAC
addresses.
3. Use the router to limit the range of IP addresses to match the
number/range of reserved IP addresses.

Then, I should not have to enter the static IP information on the
client. Correct?

rsquared