Intermittent DNS issues

[nala1]

Hello...

Everyday and at varying times it looks like DNS isn't functioning. First, if I attempt to open my mailbox in Lotus Notes I receive "The remote server is not a known TCP/IP host" PLUS at the same time I am unable to telnet to a server, e.g. a UNIX box. This lasts approximately 5 minutes and then suddenly I can access mail again as well as telnet by name successfully. This happens daily but at different times. It's not just my machine but users all over our network as I will receive phone calls that someone can't get into their email. My only solution for them is to keep trying and within 5 minutes they should be able to open their mail. Does any have any ideas as to what's going on?
Thank You

 

[Castor66]

If you get the error message then open a command prompt and enter

ipconfig /flushdns

Then try again immediately - what happens?

Can you also check using an nslookup or a dig of the name?

 

[Saugilsr]

Also, when it goes down I would immeadetly try and ping (using the IP address) the DNS to see if its a network problem. It sounds kind of like an iffy network card/connection. Are any other services located on that DNS server? Do you only have 1 DNS server?

 

[nala1]

We have 2 DNS servers. The first is the primary DC and also houses RRAS. The second is also a DC, WAS a DHCP server (not anymore), runs WINS, and RRAS.
I was able to ping by IP successfully to either DNS server.

 

[Saugilsr]

Are the DNS servers Active Directory intergrated? Does it appear they are replicating properly?
Try using nslookup and resolve the mail server. Then while still in nslookup use the "server dns-ip"command to switch dns servers and resolve it again and see if you get the same result.

Im assuming that there are no event logs saying that the DNS service has stoped and restarted.

 

[nala1]

As soon as it happens again (and I notice it) I will try the above.

No, there are no errors in the event logs.

 

[GlenJohnson]

How long has this been going on? Anything change that you know of? Good luck.

Click here to learn How to help with tsunami relief...

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Glen A. Johnson
If you're from Northern Illinois/Southern Wisconsin feel free to join the Tek-Tips in Chicago, Illinois Forum.
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[nala1]

This has been going on for atleast a YEAR! that I know of. I'm not sure how to answer the changes question. One of the domain controllers NIC card was changed atleast once, we've moved DHCP to several different servers since the new network admin came aboard; unfortunately, I can't answer that question intelligently especially since I am not the network administrator and have no idea what's been done, if anything. It's frustrating.

Thank you everyone for all your input. Please keep me in mind and should anything turn up please let me know! This is an ongoing problem that needs a resolution! Any help is greatly appreciated!

 

[Saugilsr]

Do you know if the network admin is doing anything about it? Can they join this thread?
Did you check if both DNS servers are replicating properly?

 

[nala1]

I hate to say anything negative about fellow employees however in this case I'd say he's done nothing about it. When I run netdiag on one of the DC's, it fails on the DNS registration - still. SO it hasn't been dealt with for well over a year because this error has been ongoing. This is probably why we have the problems that started this whole thread. Thanks, I took it for granted that the netdiag error had been taken care of. I would say at this point I can't go any further until the above is corrected.

Thank you

 

[ITPangaeaArchitect]

be sure if your routers and/or switches have spanning tree capablilties that you have portfast enabled.

be sure in the tcp/ip properties you have set the following:
wins tab-enable netbios over tcp/ip
dns tab-PDC should point to himself and himself only
replica DC should have PDC as preferred and itself as alternate
register this connections address in dns should be checked
append primary and connection specific dns suffixes should be marked
append parent suffixes... should be checked
all else but DNS server addresses should be blank

if you truly have a DNS problem though, at least 1 replication function will be broken, most likely, file replication service (although I would also expect AD replication issues)

-Brandon Wilson
MCSE00/03, MCSA:Messaging, MCSA03, A+
almost got a paragraph there

 

[GlenJohnson]

The easiest thing might be to mention this site to the admin. Tell him you found this really great site that helps for free. (Just don't mention this thread.)


Click here to learn How to help with tsunami relief...

http://www.google.com/tsunami_relief.html

Glen A. Johnson
If you're from Northern Illinois/Southern Wisconsin feel free to join the Tek-Tips in Chicago, Illinois Forum.
Don't forget to shop @ theTek-Tips Store

 

[pbunyon]

If your servers are performing failover and or other scheduled activities other than name resolutition then it may be a bandwidth issue?

Paul