Cisco Network Registrar

Document ID: 19054

Contents

Introduction
Prerequisites
      Requirements
      Components Used
      Conventions
Problem
Solution
      Workaround
      Resolution
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Related Information

Introduction

If you are running Windows 98 Second Edition, your system may have a problem with dynamic updates of Domain Name System (DNS) clients. This problem is described in the Microsoft Knowledge Base Article, Windows 98 Clients Not Registered with Dynamic DNS .”

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

The information in this document is based on these software versions:

• Microsoft Windows 98

• Microsoft Windows 98 Second Edition

• Microsoft Windows 2000 Server

• Microsoft Windows 2000 Advanced Server

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Problem

Computers that run Windows 98 Second Edition and that participate in a Windows 2000 domain may not have their host names registered with the DNS server.

When Windows 98 clients request an IP address from the DHCP server, they send the fully qualified domain name (FQDN) option (code 81), which indicates that the client registers itself with the dynamic DNS server. Windows 98 Second Edition clients, however, do not actually register their host names with the dynamic DNS server. Instead, they depend on the DHCP server to register their host name information with the dynamic DNS server.

Solution

Workaround

Cisco Network Registrar (CNR) 5.0 and later have the command policy allow-client-a-record-update enabled by default, which allows the client to update the DNS A record. If the client sets the flags in the FQDN option to indicate an A record update in the request, and if this feature is enabled, then the server allows the client to perform the A record update. Windows 98 SE, with this bug, does not perform the update. Thus, the DNS does not get a fully updated record for that client. The result is that you may not be able to do either a forward or reverse lookup on that client.

As a workaround, you can disable allow-client-a-record-update, which forces the DNS updates to come from the CNR DHCP server. You should also set up the DHCP server to update the DNS server, and set the DNS updates to come from the DHCP server.

To disable allow-client-a-record-update, issue this command:

nrcmd> policy policy_name disable allow-client-a-record-update

Specify the name of the policy that applies to the particular client. You may have one of these:

• a client-policy

• a client-class-policy

• a scope-policy

• a named policy referred to by the client-entry, by the client-class, or by the scope

• the system-default policy

Which of those seven possibilities applies is entirely dependent on your situation. The configuration in a more-specific policy always takes precedence over a less-specific policy.

Resolution

Microsoft has a supported fix; but this fix has not been fully regression tested with CNR, and it should only be applied to those computers that experience this problem.

To obtain the fix, contact Microsoft Product Support Services. Refer to Microsoft Help and Support , for a complete list of Microsoft Product Support Services Telephone numbers and for information on support costs.

The English version of this fix should have these file attributes or later:

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Related Information

• Cisco CNS Network Registrar Troubleshooting TechNotes
• Technical Support & Documentation - Cisco Systems