Server 2003 network connectivity problem?

[locolobo13]

Hi, newbie here. Sorry this is too long. But this problem has been puzzling me.

My DC is Windows Server 2003 with Exchange 2003. Lets call it Server1. Server2 is running Windows 2003 but is not a domain controller. Server2 is running Backup Exec.

The domain is in 5 floors,two separate buildings. The network engineers set us up with 3 VLANs. Server1 and Server2 are in separate VLANs.

Sometimes, when I log on to Server1 and try to remote to Server2 RDC fails. Checking for connectivity, in windows explorer, I get the following message when clicking on Server2.

\\Server2 is not accessible. You might not have permission to use this network resource...

It goes on to tell me to contact the network administrator. Unfortunately that is me.

I couldn't find anything corresponding to the problem in Event Viewer. The next step was to restart the DNS Server service. This generates the following messages:

Event ID 113
The DNS server could not signal the service "NAT". The error was 1168...
Event Source NETLOGON
Event ID 5781
Dynamic registration or deletion of one or more DNS records associated with DNS domain mydomain.local.' failed. These records are used by

other computers to locate this server as a domain controller (if the specified domain is an Active Directory domain) or as an LDAP server (if the

specified domain is an application partition).

Possible causes of failure include:
- TCP/IP properties of the network connections of this computer contain wrong IP address(es) of the preferred and alternate DNS servers
- Specified preferred and alternate DNS servers are not running
- DNS server(s) primary for the records to be registered is not running
- Preferred or alternate DNS servers are configured with wrong root hints
- Parent DNS zone contains incorrect delegation to the child zone authoritative for the DNS records that failed registration

USER ACTION
Fix possible misconfiguration(s) specified above and initiate registration or deletion of the DNS records by running 'nltest.exe /dsregdns' from

the command prompt or by restarting Net Logon service. Nltest.exe is available in the Microsoft Windows Server Resource Kit CD.
.

Server2 is still not accessible. In the command line, nslookup returns the correct IP address for Server2. Server1 can ping the IP address successfully but not the name Server1. Testing other computers yields the same results. The only thing I do note is Server1 can connect to the only other computer in its VLAN.

The next step I tried is to go to a workstation WS1 on another VLAN and RDC to Server1. It is successful. But in the RDC of Server1, Server1 cannot connect to WS1 thru windows explorer. Using the explorer I can connect to Server1 from WS1.

Eventually this problem goes away. Server1, connected thru RDC from WS1, can connect to the rest of the network. Exchange was connecting and working properly, I think, thru this whole exercise. From time to time other computers, workstations and servers have exhibited this behaviour.

Is this a Windows DNS problem? Or could it be related to the VLANs that are configured and managed by the routers and switches? Before I escalate this up is there something else to do?

thanks for reading this.

[SUpER CoP]

Can you try to run ipconfig /all and see if there is a gateway. If not, then remove it from the network connection and re-add it. The gateway was not showing up on the command line but existed in the network connection. This worked for me. If it is ICS then disable ICS and use NAT in RRAS. If your are using NAT in RRAS then are you using the DNS proxy? If you have the DNS proxy enabled disable it.

[locolobo13]

The gateway shows up in the command line. RRAS is unconfigured on the server. NAT is handled by the switches and routers which I don't have any control. I'm not sure what ICS is but I can't find it anywhere in the network connection.

thanx

[EINSTEIN_007]

I think that you are facing this problem due to existence of ISA and DNS on the same server. Can you check whether anything related to the problem implies upon you by reading from here - http://support.microsoft.com/default...;EN-US;q292822

[locolobo13]

Thanks Einstein_007.

I'm really not sure. The Routing and Remote Access Service is running. When I open the Routing and Remote Access module it is unconfigured and I think disabled. Anyway the first Action in the menu is "Configure and Enable Routing and Remote Access". Am I correct in assuming that ISA runs under RRAS?

I don't think WINS is running either. In the DNS module, the use WINS checkboxes are unchecked for the server. Although I haven't checked the records thoroughly yet, the Host A and PTR records look correct as far as I can tell.

I will have to study the article. I hesitate to edit the registry until I understand better.

[SpearMan]

Even i was facing one similar issue like yours, one workround is to load Netbui as a protocol on all the XP machines. It is for some interesting security problems but it works. Check the below kb artilce on how to install Netbui:
http://support.microsoft.com/default...b;en-us;301041