Article ID: 199159
Article Last Modified on 11/1/2006
APPLIES TO
- Microsoft Windows NT Server 4.0 Standard Edition
- Microsoft Windows NT 4.0 Service Pack 4
This article was previously published under Q199159
SUMMARY
Microsoft WINS stores a list of domain controller IP addresses for a specified domain in a special group record with a [1ch] suffix as its sixteenth character. As this list is replicated between WINS servers, it may accumulate obsolete addresses that are difficult to purge, especially on a large network of WINS servers. Windows NT 4.0 Service Pack 4 (SP4) provides a new feature that allows [1ch] entries to be purged and renewed.
MORE INFORMATION
The ability to purge [1ch] records is a product of an enhancement to Windows NT 4.0 Service Pack 4 (SP4) designed to help removed unwanted static [1ch] entries. Prior to Windows NT 4.0 SP4, a static special group WINS record, of which the [1ch] for a domain is an example, would not be overwritten by a dynamic entry, even with the Wins Migrate on/off feature enabled.
For additional information, see the following article or articles in the Microsoft Knowledge Base:
167806 Explanation of Advanced Options in WINS Manager
This behavior was designed assuming administratively entered entries would always need to take precedence with 1c group lists. To provide an exception when an administrator finds it necessary to replace a static [1ch] entry with a dynamic [1ch] entry, static entries are now overwritten by dynamic entries if the dynamic entry was registered with the same server as the static entry. For this feature to work, all WINS servers in a replication network must have Windows NT 4.0 SP4 installed.
Using this feature, it is possible to replicate a static [1ch] entry for a domain name, and then replace it with a dynamic entry on the same WINS server. When the static entry is replicated, it will overwrite any dynamic entries, which will eliminate any obsolete IP addresses that are part of any [1ch] list. When the static entry is then deleted and a dynamic entry is registered on the same server, the dynamic entry will then replace the static entries on other servers. As other domain controllers are added or renew their addresses, they will then be added to the domain [1ch] list.
Again, for this technique to be successful all WINS replication partners involved must have Windows NT 4.0 SP4. If a computer is running Windows NT 4 Service Pack 3 or earlier or Service Pack 5 or later, it will never overwrite its static [1ch] entry with a dynamic entry from any server. The static entry will need to be removed with the Winscl utility, available in the Windows NT 4.0 resource kit.
This behavior was changed for Windows NT 4.0 Service Pack 4 only. It was changed back again in Service Pack 5 and later to never overwrite its static [1C] entry. For additional information, click the article number below to view the article in the Microsoft Knowledge Base:
219295 WINS Replication May Overwrite or Merge Static 1C Records
REFERENCES
For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base:
166485 Removing Entries in WINS from Other Non-Existent WINS Servers
169216 Using Winscl.exe to Remove Corrupted WINS Entries by Version ID
177140 How to Remove Static WINS Entries from All WINS Servers
163409 NetBIOS Suffixes (16th Character of the NetBIOS Name)
167365 The Order That WINS Returns 1Ch Entries
171794 Migrate On/Off Does Not Allow Overwriting Static [1Ch] Mappings
184693 DNS/DHCP/WINS Release Notes for Windows NT 4.0 SP4 Update
Keywords: kbinfo KB199159
