Windows 7 / Networking


All IP-based networked devices, including computers, have routing tables. Routing tables describe the local network, remote networks, and gateways that you can use to forward traffic between networks. In networks with a single gateway, the routing table is very simple and indicates that local traffic should be sent directly to the local network, whereas traffic for any network other than the LAN should be sent through the gateway.

However, some networks have multiple gateways. For example, you might have two gateways on a LAN: one that leads to the Internet and another that leads to a private network. In that case, the local computer's routing table must describe that specific networks are available through the internal gateway and all other networks are available through the Internet gateway.

Note A client computer is most often configured with multiple routes in remote access scenarios. Specifically, if a client is using a virtual private network (VPN) connection, there might be separate routes for the networks accessible through the VPN connection, and all other traffic will be sent directly to the Internet.

Typically, computers running Windows will be automatically configured with the correct routing table. For example, network administrators will configure the DHCP server to assign a default gateway. When making a VPN connection, the VPN server will provide routing information that Windows will use to update the routing tables. Therefore, you rarely need to use the Route command to view or update the routing table.

However, if you are having connectivity problems and you are connected to a remote network or if your local network has multiple gateways, you can use Route to diagnose routing problems and even test different routing configurations. To view the local computer's IPv4 and IPv6 routing tables, open a command prompt and run the following command.

C:\>route print

Fully interpreting the routing configuration requires a detailed understanding of IP networking; however, you can quickly identify default routes for traffic being sent to your default gateway by locating the Active Route with a Network Destination and Network Mask of for IPv4 routes and an Active Route with the prefix ::/0 for IPv6 routes. Other Active Routes with a Gateway assigned cause traffic for the specific Network Destination and Network Mask to be sent through that gateway, with a preference for the route with the lowest metric.

If you must manually update the IPv4 routing table (you should typically make changes to the network infrastructure that assigned the routes to the client), you can use the route add, route change, and route delete commands. For more information, type route -? at a command prompt.

To update the IPv6 routing table, you must use the netsh interface ipv6 add|set|delete route commands.

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In this tutorial:

  1. Troubleshooting Network Issues
  2. Tools for Troubleshooting
  3. Table-1 Network Troubleshooting Tools
  4. Arp
  5. How to Identify a Problem with the ARP Cacher
  6. How to Clear the ARP Cache
  7. Event Viewer
  8. IPConfig
  9. Nblookup
  10. Nbtstat
  11. Net
  12. How to View Shared Folders on the Local Computer
  13. How to View Shared Folders on Another Computer
  14. Netstat
  15. Network Monitor
  16. Nslookup
  17. Verifying that the Default DNS Server Resolves Correctly
  18. Verifying that a Specific DNS Server Resolves Correctly
  19. Verifying Specific Types of Addresses
  20. Using TCP for DNS Lookups
  21. PathPing
  22. PathPing Output
  23. Routing Loops
  24. Performance Problems
  25. Possible Connectivity Issues
  26. No Connectivity Issues
  27. Performance Monitor
  28. Data Collector Sets
  29. Windows Resource Monitor
  30. Ping
  31. PortQry
  32. Identifying the TCP Port for a Service
  33. Windows 7 Testing Service Connectivity
  34. Determining Available Remote Management Protocols
  35. Why PortQry Is Great
  36. Route
  37. Task Manager
  38. TCPView
  39. Telnet Client
  40. Testing Service Connectivity
  41. Test TCP
  42. Windows Network Diagnostics
  43. The Process of Troubleshooting Network Problems
  44. How to Troubleshoot Network Connectivity Problems
  45. How to Troubleshoot Application Connectivity Problems
  46. Default Port Assignments for Common Services and Tasks
  47. How to Troubleshoot Name Resolution Problems
  48. How to Verify Connectivity to a DNS Server
  49. How to Use the Hosts File
  50. How to Troubleshoot Performance Problems and Intermittent Connectivity Issues
  51. How to Troubleshoot Joining or Logging on to a Domain
  52. How to Verify Requirements for Joining a Domain
  53. How to Troubleshoot Network Discovery
  54. How to Troubleshoot File and Printer Sharing
  55. How to Troubleshoot File and Printer Sharing from the Client
  56. How to Troubleshoot File and Printer Sharing from the Server
  57. How to Troubleshoot Wireless Networks
  58. Network Diagnostics
  59. How to Troubleshoot Firewall Problems