DHCP Requests Not Returned by TokenRing Routers

• Microsoft Windows NT Workstation version 3.5
• Microsoft Windows NT Server version 3.5
• Microsoft Windows for Workgroups version 3.11
• Microsoft TCP/IP-32 for Windows for Workgroups, versions 3.11, 3.11a and 3.11b

SYMPTOMS

Computers running Windows for Workgroups and TCP/IP-32 for Windows for Workgroups, and computers running Windows NT and TCP/IP may fail to obtain DHCP addresses in a routed TokenRing environment. Routers functioning as a 1542 BootP relay agents in a TokenRing environment forward the request to the DHCP server, however when the server replies back to the client, routers (including the Proteon CNX500 router), may fail to forward the packet due to the htype field in the packet. Many routers do not check the htype field and forward packets allowing the workstation to receive the servers response.

CAUSE

The Hardware Type (htype) is filled out incorrectly by the client. The type should be 6 (IEEE 802 Networks), by RFC. However, protocol analyzer traces will show (htype) = 1 (0x1) 10 MB Ethernet even on a workstation configured with a TokenRing network adapter.

RESOLUTION

Obtain and install the fix mentioned below.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.5 and TCPIP-32 for Windows for Workgroups versions 3.11 and 3.11a. This problem was corrected in Windows NT 3.51 as well as TCPIP-32 for WFW 3.11b included on the Windows NT 3.51 compact disc.

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