JSI Tip 4213. How do I troubleshoot events 4198 and 4199?

When the O/S detects a duplicate media access control (MAC) address, all network connectivity over TCP/IP to your computer will stop until the conflict is resolved and the computer is restarted. The System event log will contain one of the following:

   Event ID   : 4198   Source     : TCP/IP   Description: The system detected an address conflict for IP address                x.x.x.x with the system having hardware address                xx:xx:xx:xx:xx:xx the local interface is being disabled.    Event ID   : 4199   Source     : TCP/IP   Description: The system detected an address conflict for IP address                x.x.x.x with the system having network hardware address                xx:xx:xx:xx:xx:xx. Network operations on this system may                be disrupted as a result.

This is either a rare manufacturing mistake or you made a mistake while using LAA.

To resolve the problem, you must locate the duplicate MAC address and either replace the NIC or fix your LAA setting:

1. Log on to a working TCP/IP client.

2. Open a CMD prompt and type ping x.x.x.x. You should get a response from the duplicate computer like:

      Pinging x.x.x.x with 32 bytes of data:      Reply from x.x.x.x: bytes=32 time=10ms ttl=128      Reply from x.x.x.x: bytes=32 time=<10ms ttl=128      Reply from x.x.x.x: bytes=32 time=<10ms ttl=128      Reply from x.x.x.x: bytes=32 time=<10ms ttl=128

4. Type ARP -a x.x.x.x. You should receive:

      Internet Address  Physical Address      x.x.x.x xx:xx:xx:xx:xx:xx  <-- matches the event log entry

5. Type NBTSTAT -A x.x.x.x where -A is case sensitive. The reply should indicate the NetBIOS name of the duplicate computer:

   NAME             TYPE               STATUS   -----------------------------------------------   NTSERVER1           <00>                Unique   DOMAN-NAME          <00>                GROUP   NTSERVER1           <03>                Unique   Media access control address = xx-xx-xx-xx-xx-xx

6. If you receive HOST NOT FOUND, the duplicate is NOT NetBIOS enabled, like a Jet Direct Printer, Router, Unix box, or Novell server.

7. After replacing the NIC or fixing LAA, restart.