Updated Version of Dns.exe Fixes Several Problems (159310)
The information in this article applies to:
- Microsoft Windows NT Server 4.0 Terminal Server Edition
- Microsoft Windows NT Server 4.0
This article was previously published under Q159310 SYMPTOMS
An updated version of Dns.exe is available to fix the following problems:
- A lookup for a non-existent A record takes about 30 seconds to time out:
When the internal DNS server is queried, it goes to the root server. If
the root server returns an RCODE of 0, the Microsoft DNS server does not
respond to its client immediately. Some versions of BIND may return an
RCODE of 0. This can cause a 30 second delay at the querying client.
- Problem resolving some MX records: If a DNS client does a recursive
query to the Microsoft DNS server for an MX record and the authoritative
DNS server for that MX record returns an SOA record instead (because the
MX record doesn't exist), the Microsoft DNS server does not return that
SOA record to the client. A BIND DNS server does return the SOA record
to the DNS client even though it requested an MX record. Microsoft has
modified its DNS service to be compatible with BIND.
- BIND incompatibility: When the Microsoft DNS service receives a query
for a name that requires an authoritative lookup, and the DNS server
handling the lookup is a BIND server, it may respond with a CNAME
record, causing the name server (NS) record for the BIND server to be
overwritten in cache. The NS record is used to specify the authoritative
name server for a domain.
- When using the new WriteAuthorityNs reg key that was added in Windows NT
4.0 SP3 DNS, DNS queries will always return authority records=0 and
additional=0 instead the actual count for this.
- If you delegate a zone (such as mydepartment.mycompany.com) to a DNS
server that is not in the zone (such as
yourserver.yourdepartment.company.com), when a client does a lookup on a
host in the delegated zone, it will not succeed. If you ping the server
that the zone was delegated to (yourserver.yourdepartment.company.com)
once so that it is cached, lookups will start to succeed. The problem
was caused by a problem following the glue record that was associated
with the delegation, and it has been fixed.
- Access Violation in Dns.exe: Dr Watson may report an access violation on
a secondary DNS server when it is receiving invalid records from the
primary, and the data changes on the primary from the initial zone
transfer.
Other updates and optimizations:
- Reduced traffic to root servers: This version eliminates the automatic
root query on startup and in the timeout thread; instead, it queries the
root only when it receives a query that needs to be sent to the root
servers, and limits retrying the root servers to once every ten minutes.
- Better recursion response: This version supports direct forwarding of a
response from the remote DNS, where possible.
- Eliminates a deadlock condition hit by a few customers. At least one
person posting on the MS-DNS newsgroup reported hitting a deadlock. The
symptom of this is that the server stops responding to all requests.
- Better use of SOA in authority section: This version still has an
optimization to avoid this on local queries, but overall should be a
more "friendly" partner for remote DNS servers when sending a NAME_ERROR
or no-records response.
- Local network prioritization of queries: If there are multiple A
records, this version of the server puts the one that "fits best" first;
if none fits best, a straight round robin scheme is followed. This is
off by default but can be turned on with the new LocalNetPriority
registry flag:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNS\ParameteValue Name: LocalNetPriority
Data Type : REG_DWORD
Data : 0 or 1 (0 is disabled)
NOTE: This key does not exist by default.
For more information see the following article in the Microsoft
Knowledge base:
ARTICLE-ID: 177883
TITLE : DNS Server Stops Using Round Robin for Host Name
Resolution
- WildcardAllTypes registry flag: If on, this version of DNS will use
wildcards on all types -- even where they make no sense; this was added
for a specific customer scenario where it is used for a security check
using reverse lookup.
- Cache pollution fix: There was a recently-publicized problem where a
remote DNS returned bogus data, polluting the cache of DNS servers on
the Internet. This was used to point some traffic that would normally go
to InterNIC sites to another site. This release plugs that hole. All
data received must be for names at or below the zone for which the NS is
queried. For example, when you query the microsoft.com DNS server, you
will accept any data for microsoft.com or ntdev.microsoft.com but will
reject any data for someothersite.com.
- Non-port-53 operation: The purpose of this is to allow firewall of port
53 and still have the server go out and query the world. Anyone running
a server on a firewall who is not interested in incoming traffic may be
interested. You need to set the SendOnNonDnsPort registry key, to get
non-53 sends. If you set this to a specific port > 1024, you actually
run on that port, any < 1024 true value means you bind to any port.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNS\Paramete
Value Name: SendOnNonDnsPort
Data Type : REG_DWORD
Data : Desired Port#(53 is default)(port numbers are in decimal)
NOTE: This key does not exist by default.
- No-forward of delegations: This is on by default. If you delegate
foo.ntdev.microsoft.com to some server, that server is usually on your
lan and you do not want to go through your forwarding server to reach
it. To turn it off, set the ForwardDelegations registry key.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNS\Paramete
Value Name: ForwardDelegations
Data Type : REG_DWORD
Data : 0 or 1 (0 is disabled)
NOTE: This key does not exist by default.
RESOLUTIONTo resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the
Microsoft Knowledge Base:
152734 How to Obtain the Latest Windows NT 4.0 Service Pack
STATUSMicrosoft has confirmed that this is a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.
Modification Type: | Minor | Last Reviewed: | 9/23/2005 |
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Keywords: | kbHotfixServer kbQFE kbbug kbnetwork kbQFE KB159310 |
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