DNS Service Problems

[blubomber]

i seem to be having some weird problems with my DNS servers. I have two DNS servers in my network. One is a PDC the other is BDC. I have been running into the problem of having to restart the DNS server services. i have been using nslookup to query the dns servers and that is how i know there is a problem when i cant get an address resloved. Then i use nslookup on the other DNS server and everything works ok.

Is there anything that can be done? some utilities or something?

thank you any advice and guidance.

PS. it is a windows 2k network.

[meese]

Is this an Active Directory Domain? Are both servers w2k domain controllers? If so are you using AD integrated DNS zones or Standard Primary zones? Are you using DHCP to hand out ip's? Try shutting down one DC at a time and try to connect to the internet. Why don't you post an ipconfig /all from each DC and a client machine. I know its a lot of questions, and I have more .

[DVNT1]

I use two internal W2K AD integrated DNS servers and they run DNS services without a problem.

I would look closely at your Event Viewer to help understand what might be going wrong.

As for mionitoring the problem, an awesome yet relatively inexpensive monitoring tool is ActiveXperts Network Monitor. With it you can have it run a script upon failure (like a script to restart the DNS service).

[DVNT1]

and this might help...

DNS Log
You can configure the DNS server to create a log file that records the following types of events:

Queries
Notification messages from other servers
Dynamic updates
Content of the question section for DNS query message
Content of the answer section for DNS query messages
Number of queries this server sends
Number of queries this server has received
Number of DNS requests received over a UDP port
Number of DNS requests received over a TCP port
Number of full packets sent by the server
Number of packets written through by the server and back to the zone
The DNS log appears in % SystemRoot%\System32\dns\Dns.log. Because the log is in RTF format, you must use WordPad to view it.

You can change the directory and file name in which the DNS log appears by adding the following entry to the registry with the REG_SZ data type:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\DNS
\Parameters\LogFilePath

Set the value of LogFilePath equal to the file path and file name where you want to locate the DNS log.

By default, the maximum file size of Dns.log is 4 MB. If you want to change the size, add the following entry to the registry with the REG_DWORD data type:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\DNS
\Parameters\LogFileMaxSize

Set the value of LogFileMaxSize equal to the desired file size in bytes. The minimum size is 64 Kb.

Once the log file reaches the maximum size, Windows 2000 writes over the beginning of the file. If you make the value higher, data persists for a longer time, but the log file consumes more disk space. If you make the value smaller, the log file uses less disk space, but the data persists for a shorter time.


Caution

Do not leave DNS logging during normal operation because it consumes both processing and hard disk resources. Enable it only when diagnosing and solving DNS problems.

To configure the server to log DNS events

In the DNS console, click the box next to the server, right-click the server, and then click Properties.
Click the Logging tab, and then select the options you want to log.
Stopping and Flushing the Cache
In addition to flushing the cache by using Ipconfig, you can stop and flush the cache by stopping and starting the client.

To stop the client

At the command prompt, type the following:
net stop "dns client"

To start the client

At the command prompt, type the following:
net start "dns client"

Monitoring in the DNS Console
You can use the DNS console to perform a test query to determine whether or not your server is working properly.

To perform test queries from within the DNS console

In the DNS console, double-click the server name to expand the server information.
Right-click the server, and then click Properties.
Click the Monitoring tab.
Select the tests you want to perform, and then click Test Now.
If the simple query fails, check whether the local server contains the zone 1.0.0.127.in-addr.arpa. If the recursive query fails, check whether your root hints are correct and whether your root servers are running. For more information about simple queries and recursive queries, see "Introduction to DNS" in this book.

from http://www.microsoft.com/windows2000...f_imp_mwzz.asp

[blubomber]

Thank you for the replies.

It is and Active Directory Domain and the DNS servers are AD integrated. both servers are win2k and there is a DHCP server handing out address.

Here is why i first noticed the problem. I got a complaint from a user that they had sent email out and the intended recipient never got it. We are using exchange 5.5 and i checked the out queue and the messages were still there. I checked the details and it said that i could not resolve the address. I then ran an IPconfig and saw that only one of the DNS servers was listed. I then did an nslookup using the difault DNS server and when i tried to resolve the domain that email could not get to, i got an error. When i would switch to the other DNS server in nslookup, i could resolve the domain name fine. I did not see anything noticable in the event logs on this. i stopped and restarted the DNS server service and then i could relsolve just fine.

I ran into the same situation last night because i forgot to add the second DNS server to the exchange servers list of DNS servers. I just cant seem to pin down the problem.