Hello, May I ask again for your expertise and experience regarding our problem. We have a dc/file server (win2k8 r2) with more or less 2000 users. Earlier, some users could no longer access it via WAN or LAN. The difficult part is that not all users are experiencing the problem, also WAN & LAN. As per our network group, there was no problem on the routers, switches, connections and ports. I did not find any error logs on the evnt viewer regarding connection problems or services malfunctioning. I just noticed in resource monitor -> TCP Connection that its graph is consistently high with 60 max. Our last resort was to restart the server. After restart, all users could now connect to the server. Still no event for error logs, but in resource monitor -> TCP Connection, the graph was in the middle but its now 500 max. I'm afraid it might happen again until we can't find the cause. Have you also encountered this and have known the cause? Thanks a lot.

Hello, the problem description is not really helpful. How exactly do you realize the WAN/LAN access problem? Hopefully the DC is NOT connected with 2 NICs and used for RRAS services as VPN server or is this SBS version from Windows? But as you state Windows server 2008 R2 it seems not. For starting please post an unedited ipconfig /all from the DC/DNS server and a problem client so we can verify some basic settings. Is that the only DC in the domain, then with 2000 users please think about building a second DC/DNS/GC for failover and redundancy? This is also recommended by Microsoft.Best regards Meinolf Weber MVP, MCP, MCTS Microsoft MVP - Directory Services My Blog: http://msmvps.com/blogs/mweber/ Disclaimer: This posting is provided AS IS with no warranties or guarantees and confers no rights.

Hi, Ensure all Pc's are connected from NIC all the way to switch, and make sure that if you have changed computer name of anything like that, then try disconnecting it from a domain and re-connect it to the domain again and this could help. Thanks, Hope it helpsLewis.j.Routledge

Hi Meinolf, Thanks for the response. To clarify, our server is Win2k8 Server Standard R2 (SP1). Although we have backup DCs, its file server service have no failover/redundancy (sorry, business have limited budget for OS and HW). The server is not connected with 2 NICs and is not used for RRAS. Its' roles are DC, File Server, DNS only. Here is the scenario, Server (IP 172.21.100.XXX; SB: 255.255.252.0, GW: 172.21.100.XXX) could be ping by users in LAN. Users have the same ip range & subnet as the server. However, some users when connecting to the shared folder of the server (\\servername\) encountered error "Unable to find path" or "could not be accessed". Some users, same range and subnet, could access the server. For WAN A & B, sample IPs (172.21.30.XXX & 172.21.10.XXX) can't access with same error but can ping the server. But for WAN C (172.21.32.XXX), have no problem. After the restart of the server, all are working fine. As of now, the problem did not yet reoccured.

Hello, please post the unedited ipconfig /all as requested. The ip address infos are not really helpful this way. As you are using 172.21.x.x this is private ip range and NOT accessible from the internet so no problem with postin gthem here. Domain names or server name you can change if you have concerns about BUT keep the format of names, so DOMAIN.COM or DOMAIN for example. What kind of WAN access are you talking about, between subnets or to the internet?Best regards Meinolf Weber MVP, MCP, MCTS Microsoft MVP - Directory Services My Blog: http://msmvps.com/blogs/mweber/ Disclaimer: This posting is provided AS IS with no warranties or guarantees and confers no rights.

Ok Meinolf, WAN access are between subnets only, not via internet. This is for the server: C:\Users\>ipconfig /all Windows IP Configuration Host Name . . . . . . . . . . . . : SERVERNAME Primary Dns Suffix . . . . . . . : DOMAIN Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : DOMAIN Ethernet adapter Local Area Connection 4: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : HP NC326i PCIe Dual Port Gigabit Server A dapter #2 Physical Address. . . . . . . . . : 1C-C1-DE-F0-2C-85 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Ethernet adapter Local Area Connection 3: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : HP NC326i PCIe Dual Port Gigabit Server A dapter Physical Address. . . . . . . . . : 1C-C1-DE-F0-2C-84 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Ethernet adapter Local Area Connection 2: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : HP NC360T PCIe DP Gigabit Server Adapter #2 Physical Address. . . . . . . . . : 00-26-55-DF-27-B1 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes IPv4 Address. . . . . . . . . . . : 172.21.100.14(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.252.0 Default Gateway . . . . . . . . . : 172.21.100.1 DNS Servers . . . . . . . . . . . : 172.21.32.24 172.21.32.25 127.0.0.1 NetBIOS over Tcpip. . . . . . . . : Enabled Ethernet adapter Local Area Connection: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : HP NC360T PCIe DP Gigabit Server Adapter Physical Address. . . . . . . . . : 00-26-55-DF-27-B0 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{D852BA68-5D78-4370-9919-821172DC3561}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{F44D0065-8724-4EF3-8D06-23B984752857}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{64EE8240-B0F2-4475-AC48-894D95B74F68}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{3014D115-B538-41D7-91A9-0456A199E87B}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #4 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes This is a sample user that could not access the server from a different subnet. Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C:\Users\>ipconfig /all Windows IP Configuration Host Name . . . . . . . . . . . . : COMPUTERNAME Primary Dns Suffix . . . . . . . : DOMAIN Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : DOMAIN Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : mshome.net Description . . . . . . . . . . . : Intel(R) 82579V Gigabit Network Connectio n Physical Address. . . . . . . . . : E0-69-95-69-23-48 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::d0f4:2bda:e4dc:b490%14(Preferred) IPv4 Address. . . . . . . . . . . : 172.21.30.26(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.252.0 Lease Obtained. . . . . . . . . . : Thursday, April 12, 2012 11:41:58 AM Lease Expires . . . . . . . . . . : Monday, April 30, 2012 11:41:58 AM Default Gateway . . . . . . . . . : fe80::15b2:7ab9:b001:bdd2%14 172.21.28.10 DHCP Server . . . . . . . . . . . : 172.21.32.1 DHCPv6 IAID . . . . . . . . . . . : 299919765 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-CE-8D-7B-E0-69-95-69-66-32 DNS Servers . . . . . . . . . . . : fe80::15b2:7ab9:b001:bdd2%14 172.21.32.24 172.21.28.14 NetBIOS over Tcpip. . . . . . . . : Enabled Connection-specific DNS Suffix Search List : mshome.net Tunnel adapter isatap.{5119FE36-B7C2-4BCB-BB97-5E39C8DB5B9F}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : mshome.net Description . . . . . . . . . . . : Microsoft ISATAP Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter Local Area Connection* 11: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft Teredo Tunneling Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes

On the clinet system IP configuration, Default Gateway is showing IP V6 address and in DNS as well I can see IP V6. Can you please assign appropriate IP V4 on them and remove these IP V6 on client system and check (Note- Do not disable any of the IP V6 on Domain controllers) Regards, _Prashant_MCSA|MCITP SA|Microsoft Exchange 2003 Blog - http://prashant1987.wordpress.com Disclaimer: This posting is provided AS-IS with no warranties/guarantees and confers no rights. Email-giteepag@yahoo.co.in

Hello, on servers it is recommended to disable not used NICs. So the problem server is not DNS server, if yes please configure the real ip address instead using only the lopback ip 127.0.0.1. On the client you use "mshome.net" as Connection specific DNS suffix Search list entry, why? So the problem server is in a different subnet as the client machine according to the ip configuration? Is that a routed network or different? Any firewalls in between and which bandwitdh/speed is between the locations?Best regards Meinolf Weber MVP, MCP, MCTS Microsoft MVP - Directory Services My Blog: http://msmvps.com/blogs/mweber/ Disclaimer: This posting is provided AS IS with no warranties or guarantees and confers no rights.

Hi Prashant, Thanks for the response. We have DHCP appliance on our network group giving us these IP addresses for the computers. Could it be the main cause of the problem? Actually, this is the first time I noticed that there was an IPV6 on the computers. However, please take note that we could ping the server by its IP addresses and servername. Need to check if those without IPV6 encountered this problem. Hi Meinolf, Ok, will disable not used NICs. The problem server is a DNS server but its IP-DNS is configured to 172.21.32.24 (another DC) and a loopback as its secondary. Connection from client to server is a routed network (but as mentioned, this also happened to clients with the same subnet). For firewalls, I think there are routers which act as a firewall that disables specific ports. For the DNS suffix search, not sure why, I also did not know how "mshome.net" got there. Could it be removed? Please also note that when I restarted the problem server, the access of shared folders from the users to the server have been solved without changing config from the servers and clients.

any updates for your issue?Jeff Ren TechNet Community Support beneficial to other community members reading the thread.

Hi Jeff, Actually, the problem reoccured with the link below and after restart, it was ok with no critical error being logged on the event viewer. What we saw in the data collector sets are the following: While having error: After Restart: http://social.technet.microsoft.com/Forums/en-US/winservergen/thread/1e10818c-9de1-46d4-9e76-e4b8e5950896 Fortunately, a server replacement is scheduled this week. This server will be reformatted and we could now update the machine's BIOS and firmware as suggested by the manufacturer. Still not yet sure what is the cause but those screenshots are the only clues I got. I assume this is a machine error but what concerns me also is the difference in the resource monitor.