I have a W2K3 R2 Domain Controller (PDC, RID, Infra, GC). Some, but not all users, are experiencing very, very slow connectivity when accessing shared folders, printing or running apps hosted on this server. Things take 10-20 times longer to open. The users experiencing the slowdown vary with no discernable pattern. Some crawl while other are flying along at high speed. The trouble began when I swapped a network card about a week ago. The new card is an Intel PRO/100 PT Dual Port Server Adapter. The server had Symantec Endpoint Protection Manager installed. SEPM embeds itself quite deeply in Windows, and is real nasty when it misbehaves. When I swapped the NIC, I'd setup network teaming on the new card. I found out later that teaming is a major, documented problem for SEPM, with no known solution other than removing the team. I limped along for days, the problem came and went. Finally had enough and uninstalled SEPM last night. Uninstall didn't complete properly, and I had to use a couple very long manual removal documents from Symantec. I finally got everything removed, and cleaned up the registry following the instructions to the letter. Unfortunately, the problem with the slow connectivity came back a few hours later. For testing, I disabled the new NIC and switched over to the old one, and the problem was still there. No errors appear anywhere in the Sys/App logs on server or client. No errors in the switch (a pretty high end HP ProCurve that usually reports any errors present). Using gigabit connections all around. Verified latest drivers all around. Cabling is good. I completely uninstalled the new NIC drivers & software and reinstalled - no change. Rebooting the server doesn't help. I saw an MS article tonight http://support.microsoft.com/kb/317518 about resetting TCP/IP, basically rebuilding the stack. Not sure if this is a wise next step. I'm a long time IT Admin, but have little experience with a problem like this. I'm looking for some ideas from people with experience with this sort of thing. My gut tells me it's not hardware, but some residual problem leftover as a result of the SEPM software. I'm just not sure what to try next.MCITP Enterprise Admin/Server Admin, MCSE NT, 2000, 2003

Nobody has any ideas, eh? I've been working on this issue for days now. Here's a juicy little thing I found tonight: While file copy performance from affected PCs to slow server crawls, I can copy data from the slow server back down to the affected clients and it FLIES!! I think finding this is a breakthrough, all though I'm still at a loss. MCITP Enterprise Admin/Server Admin, MCSE NT, 2000, 2003

Hi, Thanks for posting here. Have you tried accessing server via IP address, hostname or FQDN from these affected client computers ? What’s the result ? have you also deployed any antivirus or network protection software on it ? and What’s the OS running on it? If this this slow accessing and transfer issue only occurred on these certain computers only when they try to access and copy files form server after server NIC replacement , I’d suggest that we should also troubleshoot form these client computers . Please try cleaning the ARP,DNS cache on client side first and updating the latest driver and firmware NIC or maybe resetting TCP/IP like what did you do on server side. If client is running Windows Vista, please also make sure the smb.sys driver has the update: The copy process may stop responding when you try to copy files from a server on a network to a Windows Vista-based computer http://support.microsoft.com/kb/931770 Thanks. Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.comPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, Please feel free to let us know if the information was helpful to you. Thanks, Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

<<Have you tried accessing server via IP address, hostname or FQDN from these affected client computers ? What’s the result ?>> Yes. Response to ping via IP address is immediate. But there is very slow communication using NetBIOS name and FQDN. This includes using Windows Explorer, Command Prompt, UNC name, etc. <<have you also deployed any antivirus or network protection software on it ?>> No. AV was removed, which I believe had something to do with causing the problem. The problem persisted whether the clients had AV or not. No AV on the server. <<What’s the OS running on it?>> Server: Windows Server 2003 R2 SP2 Clients: Windows 7, SP1 and non-SP1. <<If this this slow accessing and transfer issue only occurred on these certain computers only when they try to access and copy files form server after server NIC replacement , I’d suggest that we should also troubleshoot form these client computers .>> The affected clients varied, and came and went. One day Clients A & C were afffected, while another day Clients B & C, yet another day, Clients D & E. NIC drivers on server updated to most recent, same for clients. <<Please try cleaning the ARP,DNS cache on client side first and updating the latest driver and firmware NIC or maybe resetting TCP/IP like what did you do on server side.>> Did that. <<If client is running Windows Vista...>> No Vista clients. After ten straight days of this problem, yesterday was the first day we made it a full 24 hours without an affected client. On the one hand I should be "happy" the problem is gone, but on the other hand, I'm quite upset we had to deal with this issue, which was very disruptive to the business, without ever knowing what caused it. I like to find the causes to problems, especially something as serious as this. It shutdown our Accounting Dept. on several occasions. If there's anything more to report, I'll post back. MCITP Enterprise Admin/Server Admin, MCSE NT, 2000, 2003

I had a simalair issue a couple of years ago and the problem at that point was speed / duplex mismatches. I dont know this will be the same but maybe it is. regards, Eric

Hi, Thanks for update. Have you deployed WINS in your environment ? I suspect that his issue may cause due to the NetBIOS broadcast for recollect all host list form entire subnet after NIC replacement on the master browser (domain controller) in this case. Description of the Microsoft Computer Browser Service http://support.microsoft.com/kb/188001 Thanks. Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.comPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Tiger, this is the first thing I heard that actually might have been the issue. I do have a WINS server on my other domain controller (I only have two DCs). I considered name resolution as a possible issue, but couldn't make sense of it. Things have been good for 72 hours now. I think we're good. If this happened again though, I wouldn't know where to start to get it corrected. I couldn't go through another 10 day experience like this !! MCITP Enterprise Admin/Server Admin, MCSE NT, 2000, 2003