Workstations Can't Communicate with Server

To troubleshoot different kinds of workstation to server problems, see the following sections:

• Errors Reading from and Writing to Network, Server Cannot Be Found Errors.
• Connections Dropped Periodically.
• Tips for Resolving General Communication Problems.

Errors Reading from and Writing to Network, Server Cannot Be Found Errors

When workstations can't communicate with the server, users lose their connections to the server or cannot log in at all. Users might see Server Cannot Be Found messages or errors about reading from or writing to the network.

Follow these steps to troubleshoot the problem.

1. Make sure other clients can connect to the server.

   If other clients can connect to the server, then the problem is with this client, not with the server or network. Consider the following:

   • If the user cannot log in, did the user power off without logging out?

     If the user powers off without logging out, the client connection remains open and the user cannot to log in again until the connection is cleared. The server's watchdog process retries the connection a designated number of times, and then the connection times out and the server clears the connection. After the connection is cleared, the user can log in again.

     Watchdog processes are controlled by Watchdog (Communications category) SET parameters.

   • Has the user's password expired?

     Sometimes users don't understand that they must change their passwords before they use up their grace logins.

   • Are there other restrictions on the user account, such as time periods when the user is not allowed to log in? Check the user's properties.
   • Has intruder lockout been activated?
   • Is the workstation LAN cable functioning?

2. Check whether the server has had an abend.

   If the server has had an abend, it displays an abend message on the System Console screen. If the abend auto recovery process restarted the server, the message might have scrolled off the screen. Check the ABEND.LOG log file in SYS:SYSTEM to read the message.

   To troubleshoot a server abend, see Resolving Abends. For general information about types of server abends, see Understanding What Happens When You Get an Abend. To manage the abend auto recovery process, see Responding to the Abend Automatically.

3. Verify whether the server console has hung.

   If you cannot enter commands at the System Console prompt, then the console is hung. In some cases, you won't be able to toggle among server screens.

   Try pressing Ctrl+Alt+Esc. This should display a prompt to shut down the file server and exit to DOS. If the prompt is not displayed, try entering the debugger by pressing Shift+Shift+Alt+Esc. If you can enter the debugger, type q and press Enter to exit to DOS. Then reboot the server. See Server Console Hangs to troubleshoot the problem.

   If neither of the commands just described works, the only way to exit the server is to force a nonmaskable interrupt (NMI) error. Contact a Novell Support Provider or your computer hardware vendor for assistance.

   If you do not have time to obtain the assistance to generate an NMI, you can power off the server, but this can corrupt operating system files. Try this measure at your own risk.

4. Verify that volume SYS: is mounted.

   Enter VOLUMES at the System Console prompt to display a list of mounted volumes. If volume SYS: is not mounted, mount it. The server does not broadcast to the network until volume SYS: is mounted.

5. Make sure no LAN problems exist.

   In NetWare Remote Manager, click the Health Monitor link in the navigation frame, and then click the LAN Traffic link in the Description column of the Server Health Monitoring page.

   View LAN driver statistics to see if packets are being lost or if there are excessive collisions or retries. To do this in NetWare Remote Manager, click the Disk / LAN Adapters link in the navigation frame, and then click the name link for each of the network boards in your server.

   For tips on troubleshooting communications problems, see Tips for Resolving General Communication Problems

   If necessary, use LANalyzer^® or a similar product to monitor network traffic and isolate the problem.

6. Make sure server utilization is normal.

   Check utilization statistics. For help in responding to high utilization, see High Utilization Statistics.

   If you suspect heavy LAN traffic is causing the problem, try unplugging the LAN cable. If heavy LAN traffic was the problem, utilization should drop.

7. Make sure the server has sufficient resources.

   Is the server receiving No ECB Available Count messages or messages about insufficient packet receive buffers?

   These messages could indicate that the server is running out of resources. For help in resolving these errors, see Insufficient Packet Receive Buffers, No ECB Available Count Errors.

8. Make sure the eDirectory database is functioning.

   Is the eDirectory database closed or locked by another utility, such as DSREPAIR?

   If the eDirectory database is not functioning, the workstation clients will not display the login screen.

9. Check for -625 or other communication errors at the server.

   Are servers receiving -625 or other communication errors?

   If so, see Unable to Communicate with Server, -625 Errors or see the online documentation Novell Error Codes > NDS or eDirectory Error Codes.

If the problem still occurs, follow the troubleshooting steps in Using a Troubleshooting Methodology, search the Novell Knowledgebase, and contact a Novell Support Provider.

Connections Dropped Periodically

Follow these steps to troubleshoot the problem:

1. Make sure server utilization is normal.

   Check utilization statistics. For help in responding to high utilization, see High Utilization Statistics.

2. If users are using old Novell clients, upgrade them to the newest version of the applicable Novell client.

3. Make sure the node number for each workstation is unique.

4. Make sure all network boards in the server and user's workstations are working properly and are using the latest boards and drivers.

   Check Novell Knowledgebase for any known problems with your drivers and boards, update drivers, and replace boards if necessary.

5. Check all cables to make sure they are firmly connected, terminated correctly, and not running near any equipment that might cause interference.

If the problem still occurs, follow the troubleshooting steps in Using a Troubleshooting Methodology, search the Novell Knowledgebase, and contact a Novell Support Provider.

Tips for Resolving General Communication Problems

To resolve general network communication problems, do the following:

• Check all hubs and repeaters to make sure they are on. Check concentrators and look for flashing yellow lights that indicate collisions.
• Make sure all routers are functioning properly and have enough memory. A router with insufficient memory becomes the weak link in the chain and can slow down an entire LAN.
• Check the cables for proper termination. Make sure cables are not running close to sources of interference.
• Make sure the server network adapter is seated properly and is initializing. Then bring down the server, turn off the power, and check the actual network board settings:
  • Make sure all settings agree with the settings used to load the driver. If you load the driver with an interrupt that conflicts with the board's setting, the network board cannot broadcast on the network.
  • Make sure the node address on the board is a legal address. (Addresses 0 and FFFFFFFFFFFF are reserved; do not use them.)
  • Make sure that the memory range for the I/O ports and memory addresses do not overlap. If there are conflicts, reconfigure the equipment so that no conflicts exist.

• Make sure that adapters do not conflict with other boards, the monitor board, or ports in the server. Make sure no two pieces of hardware are using the same I/O port, interrupt, or memory address. Avoid interrupts 2, 9, and 15.
• Make sure the network adapter works correctly; replace it if it doesn't. Make sure drivers are the latest versions. Check the lists of certified products at Novell Solutions Search. In the Hardware Category, select LAN adapters or WAN adapters to make sure that the adapter works with NetWare. Make sure that drivers are the latest versions.
• Run VOLUMES at the server console. If volume SYS: is not mounted, mount it. The server does not broadcast to the network until volume SYS: is mounted.
• Check workstation addresses and server node numbers.

  Each node address on the network should be unique. Sometimes you can find the problem by turning off all workstations and then turning them back on one at a time.

• Make sure workstations are using the correct frame type.
• Have a user log in to the network from a workstation. In NetWare Remote Manager, click the Connections link in the navigation frame.

  If the Connections list shows the user's login name, the server is receiving and responding to the workstation's request.

  If the workstation receives a Server Cannot Be Found error, make sure the server and workstation are using the same frame type.

  If using 10baseT, try using a cross-cable to connect the server directly to the workstation. If this solves the communication problem between the server and workstation, then something on the network is causing the problem.