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Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. TCP/IP communication troubleshooting guidance
In this articleThis article is designed to help you troubleshoot TCP/IP communication issues. The ping command is useful to test basic connectivity. However, you shouldn't rely upon it to prove overall connectivity. Telnet and PsPing are more useful, for the following reasons:
Troubleshooting checklistStep 1: Capture a network diagramCapture a network diagram that details the devices that are in the path to the affected area. Specifically, note the following devices:
The diagram can help you visualize and identify where to look for the cause of the issue. Step 2: Networking tracesNetworking traces are useful to see what's occurring at the network level when the issue occurs. Step 3: Ping the computer's local IP addressTry to ping the computer's local IP address. If the node can’t ping its local IP, the local stack isn't working. Note any error messages that are displayed. If you receive a General Failure error, this error means that there are no valid interfaces to process the request. This issue could be caused by a hardware issue or a stack issue. Check whether you see a red "X" character or a yellow exclamation mark on the Network Connection icon in the system tray. A red X indicates that Windows isn't detecting a network connection. A yellow exclamation mark indicates that the Network Connection Status Indicator (NSCI) failed a probe check. To troubleshoot this issue, verify that the network adapter reports connectivity. Make sure that the network adapter is plugged in and that the switch port where the node is connected isn't in an error state. You can change cables, switch ports, and network adapters to narrow down where this issue occurs. However, ultimately, the issue is outside the OS. To investigate further, contact the hardware vendors. An issue might also occur between the network driver and Windows. This issue is typically because of a corruption in the stack. Use the following troubleshooting steps:
If the NSCI fails its probe check (yellow exclamation mark), this doesn't necessarily indicate a connectivity problem. Make sure that typical communication is occurring as it should.
Step 4: Troubleshoot error messages that occurs during the ping or telnet testIf the node can ping or telnet to nodes on the same subnet or network segment, this would confirm that external connectivity is working. Further testing is still required to understand whether a basic connectivity issue exists. If the node can’t ping/telnet to nodes on the same subnet/network segment. Note any error messages that are displayed.
Step 5: Ping or Telnet to the default gatewayWhen the node can ping its default gateway, then external connectivity (such as off-box connectivity) is possible from the source node. Further testing would still be required to understand whether a basic connectivity issue exists. If the node can’t ping or Telnet to its default gateway, this means that the ICMP replies are disabled on the router. Step 6: Check issues that affects the specific destination nodeIf the source node can ping, Telnet, or PsPing to other nodes on the destination subnet, then basic connectivity and routing within the infrastructure is working. This outcome points to an issue that affects the specific destination node.
Common issues and solutionsTCP/IP connection to a host appears to have stoppedThis issue occurs because either data is blocked in TCP and UDP queues or there are network or user-level software delay problems. To troubleshoot this issue, use the netstat -a command to show the status of all activity on TCP and UDP ports on the local computer. Long connect times when using Lmhosts for name resolutionThis issue occurs because the Lmhosts file is parsed sequentially to locate entries without the #PRE option. To troubleshoot this issue, put frequently used entries near the top of the file and the #PRE entries near the bottom. If an entry is added to the end of a large Lmhosts file, mark the entry in Lmhosts as a preloaded entry by using the #PRE option. Then, run the nbtstat -R command to update the local name cache immediately. System error 53 occurredSystem error 53 is returned if name resolution fails for a particular computer name when the net use command is used. If the computer is on the local subnet, verify that the name is spelled correctly and that the target computer is also running TCP/IP. If the computer isn't on the local subnet, make sure that its name and IP address mapping are available in the Lmhosts file or the WINS database. If all TCP/IP elements appear to be installed properly, use the ping command together with the remote computer to verify that its TCP/IP software is working. Can't connect to a specific serverThis issue occurs because either NetBIOS name resolution isn't resolving the name or the wrong IP address is being resolved. To troubleshoot this issue, use the nbtstat -n command on the server to determine which names the server registered on the network. The computer name of the computer that you're trying to connect to should be on the displayed list. If the name isn't listed, try one of the other unique computer names that are displayed by nbtstat. If the name that's used by a remote computer is the same as the name that's displayed by the nbtstat -n command, make sure that the remote computer has an entry for the server name that's on the WINS server or in its Lmhosts file. Unable to add a default gatewayThis issue occurs because the IP address of the default gateway isn't on the same IP network ID as your IP address. To troubleshoot this issue, determine whether the default gateway is located on the same logical network as the network adapter of the computer by comparing the IP address of the default gateway with the network IDs of any of the network adapters of the computer. For example, a computer has a single network adapter that's configured with an IP address of 192.168.0.33 and a subnet mask of 255.255.0.0. This requires that the default gateway to be of the form "192.168.<y>.<z>" because the network ID portion of the IP interface is 192.168.0.0. Data collectionBefore contacting Microsoft support, you can gather information about your issue. Prerequisites
Note If the current PowerShell execution policy doesn't allow running TSSv2, take the following actions:
Gather key information before contacting Microsoft support
The traces will be stored in a zip file in the C:\MSDATA folder, which can be uploaded to the workspace for analysis. Reference
How do you troubleshoot a TCP connection?Check the TCP/IP services configuration file. Verify that a SequeLink service is listening on the server host at the specified port. Use the netstat -a command on the host to obtain a list of TCP ports that are in the listening state. Check for congestion problems on the server.
What commands can be used to troubleshoot TCP IP?Chapter 6 Troubleshooting TCP/IP. "General Troubleshooting Methods". "Running Software Checks". " ping Command". " ifconfig Command". " netstat Command". "Logging Network Problems". "Displaying Packet Contents". How do I troubleshoot an IP problem?How to Troubleshoot a Network. Check the hardware. When you're beginning the troubleshooting process, check all your hardware to make sure it's connected properly, turned on, and working. ... . Use ipconfig. ... . Use ping and tracert. ... . Perform a DNS check. ... . Contact the ISP. ... . Check on virus and malware protection. ... . Review database logs.. What protocols are used in TCP?TCP/IP Protocol Architecture Model. |