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How to Connect Remote System through Internet?

Connection / December 11, 2021

If the problem is not NetBIOS but Sockets, the problem is related to either a Hosts file or a DNS configuration error. To determine why only IP addresses but not host names work for connections to remote computers, make sure that the appropriate Hosts file and DNS setup have been configured for the computer.

To check host name resolution configuration

  1. In Control Panel, click the Network and Dialup Connection icon.
  2. Right-click Local Area Connections, and then select Properties .
  3. Click on Internet Protocol (TCP/IP) , and then click Properties .
  4. Click the Advanced tab in the Microsoft TCP/IP Properties dialog box.
  5. Click the DNS tab.
  6. Confirm that DNS is configured properly. If the DNS server IP address is missing, add it to the list of DNS server addresses.

Note that this procedure does not take DHCP clients into account; these clients do not have DNS server in the list.

Check the Hosts File

If you are having trouble connecting to a remote system using a host name and are using a Hosts file for name resolution, the problem may be with the contents of that file. Make sure the name of the remote computer is spelled correctly in the Hosts file and by the application using it.

The Hosts file or a DNS server is used to resolve host names to IP addresses whenever you use TCP/IP utilities such as Ping. You can find the Hosts file in \% SystemRoot %\System32\Drivers\Etc.

This file is not dynamic; all entries are made manually. The file format is the following:

The IP address and friendly host name are always separated by one or more space or tab characters.

Host Name Resolution Using a Hosts File

A computer using its Hosts file for name resolution performs the following steps.

  1. Computer A enters a command using the host name of Computer B.
  2. Computer A parses its Hosts file (in \% SystemRoot %\System32\Drivers\Etc), looking for the Computer B host name. When the host name of Computer B is found, it is resolved to an IP address.
  3. The resolved IP address is passed to the IP routing component. The routing component returns either a routing error because a route was not found for the destination IP address or the forwarding IP address and interface over which the packet is to be forwarded cannot be found.
  4. ARP resolves the forwarding IP address to a hardware address.

The following Hosts file problems can cause networking errors:

  • The Hosts file does not contain the particular host name.
  • The host name in the Hosts file or in the command is misspelled.
  • The IP address for the host name in the Hosts file is invalid or incorrect.
  • The Hosts file contains multiple entries for the same host on separate lines. Because the Hosts file is parsed from the top, the first entry found is used.

Check Your DNS Configuration

If you are using DNS, be sure that the IP addresses of the DNS servers are correct and in the proper order. Use Ping with the remote computer's host name and then with its IP address to determine whether the host address is being resolved properly. If the host name ping fails and the IP address ping succeeds, the problem is with name resolution. You can test whether the DNS servers are running by pinging their IP addresses or by opening a Telnet session to port 53 on the DNS server. If the connection is established successfully, the DNS service is working on the DNS server. Once you've verified that the DNS service is running, you can perform NSLookup queries to the DNS server to further verify the status of the records you are looking for.

If ping by IP address and by name fail, the problem is with network connectivity, such basic connectivity or routing. For more information about troubleshooting network connectivity, see "Troubleshooting IP Routing" later in this chapter.

Host Name Resolution Using a DNS Server