3c595 Adapter Auto-Detects Wrong Media Speed

• Microsoft Windows NT Workstation, version 3.5 and 3.51
• Microsoft Windows NT Server, version 3.5 and 3.51

SYMPTOMS

When a Windows NT system with a 3Com 3c595 Fast Ethernet adapter starts its network services, other Windows NT systems with 3c59x cards and located on the local network segment lock up.

CAUSE

The 3c595 Ethernet adapter, which is compatible with both 10 MB/s and 100 MB/s Ethernet segments, is improperly detecting the 10 MB/s Ethernet segment as a 100 MB/S Ethernet segment.

RESOLUTION

Use the 3Com adapter configuration utility for the 3c595 NIC to force the media type setting to 10 MB/s. To do this, use the following procedure:

1. Boot the Windows NT system with an DOS-bootable disk (the configuration disk is NOT bootable by default).

2. From the root of the floppy disk, type 3C59XCFG.EXE and press ENTER.

3. From the menu, select "Install" and "Configure Adapter".

4. From the "Adapter Configuration" window, select "Media Type".

5. From the "Media Type" window, select "10 base-T (RJ-45) (10 Mbits)".

6. Click "OK." The specified settings will now be saved to the adapter.

7. Remove the floppy disk from the drive and reboot the system.