LAN dropouts/"specified network name is no longer available" accessing PDC

By mhamer ·
Hi there

Have a huge issue at a workplace that I have been drafted in to solve that is driving me insane for 3 days. The previous IT guy in charge left some time ago and so the company has had no network/IT support in the meantime, and there are no handovers of any kind. What a great start! I would really love some help on this one; as of issues described as above i haven't fully got to grips with the network setup and so me myself and I have really been thrown in right at the deep end.

The main issues on this 100-150 node LAN is that all clients (Win2k and WinXP) are losing their connection randomly to their shares if an explorer window of that share or an app on that share isn't left open (regardless of leases expiring etc) The WinXP machines can resolve this issue fairly easily by using the Repair network function. The Win2k machines don't have this; a dodgy batch file on some of these machines occasionally does the same thing, but has never worked for me when I've tried. Shared printers which are connected directly to client machines via USB randomly drop away too. One minute they appear Ready, next they appear offline.

The majority of machines I've seen have been given Auto IP addressing on the client and then given a fixed IP address by the DC in the DNS settings. Some of these appear to conflict which is a bit worrying and I have already ensured each machine is now given one unique IP address. (First sign of trouble).

The Win2k machines have been a nightmare. They can always see machines pop up under Entire Network/OurDomainName, regardless of the fact if it is joined to the Domain or not, or whatever workgroup name is given if i drop it out. The client machines are listed in the entire network in sequential fashion, and the DC is also listed (SRV2000 for example).

On this SVR2000 is a share that everyone in the building needs access to. However, the Win2k machines grind to a halt with error "The specified network name is no longer available" . SVR2000 is always visible and only sometimes accessible. In 3 days i have found absolutey no way to predictably replicate the problem - sometimes it will connect and others it will not (usually not - ha) Sometimes it works after restarting, others not. I can find absolutely no pattern - very annoying.

I have tried giving manual addressing on the client, auto-iping, deleting the machine's DNS entries on the DC, giving only the DNS server and auto IP, creating it as a "new" machine and removing it from the domain then rejoining it (which took some doing also - creating a brand new local admin account on that particular machine seemed to do it as opposed to using the exisiting local Administrator account...bizzare). Still the exact same problem.

The setup as far as i can tell is as follows: One PDC running W2kSBS, running AD, WINS and DNS, a seperate W2k3 server running Oracle databases engines only (installed by a 3rd party company), all connected to hub along with a WAP, these are behind firewall pc, then firewall modem, then internet.

From searching forums aplenty most of it would sways towards a DNS/WINS issue. However, for all i know it could be a dodgy switch somewhere. this is a 7 day live network and I want to be more sure where the fault lies before I start making major changes/overnight maintainence. Apparently the dude who set it up wasn't 100% with what he was doing.

Is it wise to remove all the DNS/WINS records and start again from scratch? Is it better to assign the IP addresses on the client machines and not with a DNS/DHCP combo as is now?

This is the largest network I've had to troubleshoot before personally and so it's a toughie. I spoke with the guy who installed the 3rd party w2k3 server and he agreed.

Does anyone have any ideas???

Thanks in advance!

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All Answers

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DNS is most likely an issue

by w2ktechman In reply to LAN dropouts/"specified n ...

as WINS play a very small role in AD nets.
Setup a separate system as a second DNS server, or if you have multiples, take 1 offline to change settings. Leave the primary DNS server in place.

After hours, test with the new DNS settings and if it looks good, set a login script to remap primary DNS to your new server.
Be ready to remap to the old primary if things fail.

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It's probably the "Master Browser"

by spedia999 In reply to LAN dropouts/"specified n ...

Go into Services and change the Computer Browser to "manual" it's probably already started, so you'll want to stop it.

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if this is a SBS network

by CG IT In reply to LAN dropouts/"specified n ...

if you disabled DHCP your broke SBS and you'll have a **** of a time activating and authorizing DHCP.

It is NOT WISE to remove DNS in any Active Directory environment. You'll break AD and have to start from a full backup.

First question, do you have a valid full system backup?

second question: did anyone remove DHCP on the SBS box? unauthorize or deactive DHCP?

Third question: SBS is almost entirely wizard driven. If you try to manually configure DNS, DHCP, you'll end up breaking stuff. Always run the wizards. Tweeking the setup is ok but never try to set stuff up or reinstall without using the SBS wizards.

4th question. is this a single NIC or dual NIC configuration?

5th. how do you join comps to the domain? use the connect computer wizard? do you create computer accounts FIRST in the My Business/SBS/Computers OU before you run
the wizard? or do you use the System/Computer Name method of joining the domain? when removing the computer did you join it to a workgroup, then join the domain again?

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check xour firewall

by cnissim In reply to LAN dropouts/"specified n ...

I had the same problem and solved it by opening the firewall on the destination machine

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The specified network name is no longer available

by tuanba In reply to LAN dropouts/"specified n ...

Check the Windows Service:
Computer Browser
It is started ?

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LAN dropouts

by pcprp_on_wheels In reply to LAN dropouts/"specified n ...

This is a "no-duh" thing but often overlooked. Make sure the system time on all machines are pretty well synchronized.

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by shroomos In reply to LAN dropouts/"specified n ...
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Any Luck on Fixing this?

by thesurg3on In reply to LAN dropouts/"specified n ...

I have the exact same problem.

Disabled A/V
Disabled Firewall

Copying from File Server to Domain controller. The Computer Browser is enabled on both. Should I disable it on the Domain Controller? Or both?

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What's with the Zombie posts? This one is 2006

by CG IT In reply to LAN dropouts/"specified n ...

Sheesh now they gotta dig in the archives...

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You had some learnign to do in 06

by mlafflin In reply to What's with the Zombie po ...

1- you needed to scavenge stale DNS records
2- DHCP from server always.

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