Questions

clients getting address from 2000 server, but not from DHCP

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clients getting address from 2000 server, but not from DHCP

jeff
I am running 2000 advanced server, with RAS and DHCP. The problem is, something is answering DHCP requests other than the DHCP server. If I dissable the DHCP server, RAS, and DNS, client requests are still answered. Since I am using RAS, internet sharing is dissabled. I have two NICs, 10.10.1.1 and a 192.168.0.1. The DHCP server has two scopes set up to assing 10.10.1.100-10.10.1.254 and 192.168.0.100-192.168.0.254. It appears whatever else is answering requests is alternating. In other words, every other time you'll get a 192.168.0.100-254, the other times you'll get a 192.168.0.2-x. Any ideas what service may be doing this?
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    On a Windows OS, usually only the DHCP server handles DHCP/BOOTP requests. However....could there be a switch, router, firewall, or appliance that is configured as a DHCP server?

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    rkuhn

    I'm betting you're at home and have a router such as D-Link or LinkSys and it is serving your DHCP for you since your clients are setup in their TCP/IP settings as dynamic.

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    jeff

    There is no other hardware. I do have a d-link access point, but it is set to access point mode, disabling the DHCP server and NAT, and I discconected everything else from the server, and connected just my laptop to it, and still pulled an address from something other than the DHCP scope.

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    Well if you have "disabled" (stopped services I assume) DHCP and RAS on your server and your laptop is still "pulling" an IP address (you released and renewed I assume), and there is no other hardware involved....
    I noticed one of the IP addresses that are being assigned to your client is not in your DHCP scope. If you are running wireless, could there be another unsecured wireless network nearby that you are unknowingly connecting to?

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    bart777

    From a machine that is getting this address, run an IPCONFIG /release and renew.

    Once you've done that then do an IPCONFIG /ALL. This should show you the address of the DHCP server that is handing out the address. From there you should be able to kill it.

    Good hunting.

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    jeff

    Nope. I did a repair of the connection, with a wired connection to the switch, with nothing else attached to the switch, just the server and my laptop. I then disconnected the server to prove that is where the IP address is coming from, with the server disconnected no ip address was assigned. When the wrong IP address is assigned, my laptop does show the 192.168.0.1 as the DHCP server, so I am 99.9% positive something is running on the server passing out IP addresses other than the DHCP server.

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    alphatech9

    I disable DHCP on the server, but the router was pulling in a IP from the ISP. the IPs coming back were like 74.112.23.XX but the scope in the server and router were both 192.168.x.x.

    This is common for a laptop to show a different IP than what is configured in the server.

  • +
    0 Votes

    On a Windows OS, usually only the DHCP server handles DHCP/BOOTP requests. However....could there be a switch, router, firewall, or appliance that is configured as a DHCP server?

    +
    0 Votes
    rkuhn

    I'm betting you're at home and have a router such as D-Link or LinkSys and it is serving your DHCP for you since your clients are setup in their TCP/IP settings as dynamic.

    +
    0 Votes
    jeff

    There is no other hardware. I do have a d-link access point, but it is set to access point mode, disabling the DHCP server and NAT, and I discconected everything else from the server, and connected just my laptop to it, and still pulled an address from something other than the DHCP scope.

    +
    0 Votes

    Well if you have "disabled" (stopped services I assume) DHCP and RAS on your server and your laptop is still "pulling" an IP address (you released and renewed I assume), and there is no other hardware involved....
    I noticed one of the IP addresses that are being assigned to your client is not in your DHCP scope. If you are running wireless, could there be another unsecured wireless network nearby that you are unknowingly connecting to?

    +
    0 Votes
    bart777

    From a machine that is getting this address, run an IPCONFIG /release and renew.

    Once you've done that then do an IPCONFIG /ALL. This should show you the address of the DHCP server that is handing out the address. From there you should be able to kill it.

    Good hunting.

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    0 Votes
    jeff

    Nope. I did a repair of the connection, with a wired connection to the switch, with nothing else attached to the switch, just the server and my laptop. I then disconnected the server to prove that is where the IP address is coming from, with the server disconnected no ip address was assigned. When the wrong IP address is assigned, my laptop does show the 192.168.0.1 as the DHCP server, so I am 99.9% positive something is running on the server passing out IP addresses other than the DHCP server.

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    0 Votes
    alphatech9

    I disable DHCP on the server, but the router was pulling in a IP from the ISP. the IPs coming back were like 74.112.23.XX but the scope in the server and router were both 192.168.x.x.

    This is common for a laptop to show a different IP than what is configured in the server.