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  • #2225530

    Strange IP Address Conflict !

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    by krishi_reddy ·

    Hi all,

    I have a strange IP Address Conflict in my win 2003 server which I am unable to resolve…please help me.

    I have Windows 2003 server SP1 installed with Symantec AV Corporate edition. Server is not a domain Controller and is not DNS/DHCP configured.I have 2 NICS, one connected to broadband Internet connection ADSL Router which has DHCP enabled. I have 4 PCs connected to this LAN and I am using ICS. All nodes get IP dinamically.

    But the problem is I am getting IP address conflict message error in win 2003 server and Network goes down untli I restart server. The network is fine for sometime or some hours and suddenly I get IP conflict error and Internet is down ! I get this error is server only…not in any other system so that I am unable to figure out which systems is giving problems.

    NIC 1 is directly connected to ADSL router and router IP is 192.168.1.1 NIC address is 192.168.1.2

    NIC 2 has automatically got 192.168.0.1 when I checked Internet connction sharing.

    All nodes connected are configured to take IP dinamically..

    Please help me in this issue….

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    • #2619135

      Clarifications

      by krishi_reddy ·

      In reply to Strange IP Address Conflict !

      Clarifications

    • #2800690

      I have the same here

      by fawezy ·

      In reply to Strange IP Address Conflict !

      i have the same here, how did you resolve it.

      I changed everything and still the same.

    • #2796783

      Re: Strange IP Address Conflict !

      by Anonymous ·

      In reply to Strange IP Address Conflict !

      What Is an IP Address Conflict?

      Answer: An IP address conflict occurs when two computers on a LAN (local area network) or the Internet have been assigned the same IP address. IP conflicts between two computers normally render either one or both of them unusable for network operations.
      How IP Address Conflicts Happen
      Two computers can acquire conflicting IP addresses in any of several ways:

      * A system administrator assigns two computers on the LAN the same static IP address

      * A system administrator assigns a computer a static IP address within the local network’s DHCP range (dynamic IP range), and the same address is automatically assigned by the LAN DHCP server.

      * A malfunction in the network’s DHCP server allows the same dynamic address to automatically be assigned to multiple computers.

      * An Internet Service Provider (ISP) accidentally assigns two customers the same IP address (either statically or dynamically).

      * A mobile computer is put into standby / hibernate mode and then awakened later.

      Note that other forms of IP conflicts can also occur on a network. For example, one computer may experience an IP address conflict with itself if that computer is configured with multiple network adapters. System administrators may also create IP conflicts by accidentally connecting two ports of a network switch or router to each other.
      Recognizing IP Address Conflicts
      On most Microsoft Windows computers, if you attempt to set a fixed (static) IP address that is already active on the local network, you will receive the following pop-up error message:

      The static IP address that was just configured is already in use on the network. Please reconfigure a different IP address.

      On newer Microsoft Windows computers having dynamic IP conflicts, you should receive a balloon error message in the Taskbar as soon as the operating system detects the issue:

      There is an IP address conflict with another system on the network.

      Sometimes, especially on older Windows computers, a message similar to the following may instead appear in a pop-up window:

      The system has detected a conflict for IP address…

      On Mac or Linux computers, a similar message will normally appear on screen.
      Resolving IP Address Conflicts
      Try the following remedies for IP conflicts:

      1. For networks where IP addresses are fixed (statically assigned), ensure each local host is configured with a unique IP address.

      2. If your computer has a dynamically assigned address, releasing and renewing its IP address can workaround IP address conflicts. See also – How to Release / Renew IP Addresses on Windows

      3. If your home router is believed to have a faulty DHCP server causing IP conflicts on the home network, upgrading the router firmware may resolve this problem.
      http://compnetworking.about.com/od/workingwithipaddresses/f/ip_conflict.htm

      Please post back if you have any more problems or questions.
      If this information is useful, please mark as helpful. Thanks.

    • #2796779

      What are the IPs of the 4 workstations?

      by bens ·

      In reply to Strange IP Address Conflict !

      That might tell you who has a conflicting address to start with. Check out your DHCP leases on the ADSL router. That would be a starting point…

    • #2796743

      My first suggestion would be

      by dumphrey ·

      In reply to Strange IP Address Conflict !

      to assign static ip on nic 1 to DSL router. Static IP on the Server LAN nic, and only use the DHCP on the LAN clients.

      {internet} <---DHCP--> [DSL router] <---static IP--> [nic1 Server2003][Nic2 Server] <--static ip--< {lan clients on DHCP} My next question, is the DSL router also wireless? It sounds to me as if the nic between the dsl and server is getting the conflict. Between the DSL and Server 2003 nic 1 should be one network, like 192.168.0.0/30 (2 usable addresses), and on nic 2 another network, 192.168.1.0/24. With static addressing, it becomes easyer to find the conflict in DHCP. Document your ip addressing in an Spread Sheet for simplicity.

    • #2796678

      Here’s a start: Check ISP’s DHCP service.

      by kenrwoodson ·

      In reply to Strange IP Address Conflict !

      I have same setup as you, in regards to a machine connected to DSL router.

      I’ve tested your prob with my PC.
      Below is from my PC’s cmd prompt,
      so goto your cmd prompt and type “INPUT” of steps below.
      Just pay attention to the 2 lines of “OUTPUT” results.
      —————————————-
      [STEP 1 INPUT:]
      C:\COMPUTER>ipconfig

      [STEP 1 RESULT:]
      Windows IP Configuration
      Ethernet adapter Local Area Connection:
      IP Address. . . . . . : 192.168.1.2
      Subnet Mask . . . . . : 255.255.255.0
      —————————————-
      [STEP 2 INPUT:]
      C:\COMPUTER>ipconfig/release

      [STEP 2 RESULT:]
      Windows IP Configuration
      Ethernet adapter Local Area Connection:
      IP Address. . . . . . : 0.0.0.0
      Subnet Mask . . . . . . : 0.0.0.0
      —————————————-
      [STEP 3 INPUT:]
      C:\COMPUTER>ipconfig/renew

      [STEP 3 RESULT:]
      Windows IP Configuration
      Ethernet adapter Local Area Connection:
      IP Address. . . . . . : 192.168.1.2
      Subnet Mask . . . . . : 255.255.255.0
      —————————————-

      This checks how you ISP renews DHCP leases.
      If results are similar to your PC above, then DHCP renews fine.

      ALTHOUGH, check lease time with this cmd:
      C:\COMPUTER>ipconfig/all

      then check these lines:

      Lease Obtained. . . . . . . . . . : Wednesday, October 15, 2008 2:37:55 PM
      Lease Expires . . . . . . . . . . : Wednesday, October 15, 2008 3:37:55 PM

      Try ipconfig/all command again at a time when your DHCP issue happens. If the IP addr is different than 192.168.1.2, then whatever is offering DHCP may be faulty.

      OR:
      Try disconnecting one of your PCs that is not the server and operate server for a while. If server is doing fine, then DHCP servicer only wants to give you 3 long leased IPs.

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