Detailed explanation and use of the route command

The route command is used to display and modify entries in the local IP address routing table. Use a ROUTE without parameters to display help.

Syntax:

Route [-f] [-p] [command [destination] [mask netmask] [gateway] [metric] [if interface]

Parameter description:

-F

Clear all routes that are not the master route (the subnet mask is 255.255.255.255), round-back network route (the destination is 127.0.0.0, And the subnet mask is 255.255.255.0), or Multicast Route (the destination is 224.0.0.0, route table of the entry whose subnet mask is 240.0.0.0. If it is used with one of the commands (such as Add, Change, or Delete), the table is cleared before running the command.

-P

When used together with the Add command, specify that the route is added to the Registry and initialize the IP route table when starting the TCP/IP protocol. By default, the added route is not saved when the TCP/IP protocol is started. When used with the Print command, the permanent route list is displayed. All other commands ignore this parameter. The location of permanent routing stored in the registry is HKEY_LOCAL_MACH/SYSTEM/CurrentControlSet/Services/Tcpip/Parameters/PersistentRoutes.

Command

Specify the command to run. The following table lists valid commands.

Destination

The Network destination address of the route. The destination address can be an IP address (the host address bit of the network address is set to 0), the host route is an IP address, and the default route is 0.0.0.0. Mask

Subnetmask

Specifies the netmask (also known as the subnet mask) associated with the target network address ). The subnet mask can be an appropriate subnet mask for the IP address and 255.255.255.255.255 for the host route.

The default route is 0.0.0.0. If this parameter is ignored, the subnet mask 255.255.255.255 is used. When defining a route, the destination address cannot be more detailed than the corresponding subnet mask due to the relationship between the destination address and subnet mask. In other words, if one of the subnet masks is 0, the corresponding bit in the target address cannot be set to 1.

Gateway

Specify the previous or next hop IP address that exceeds the reachable address set defined by the Network target and subnet mask. For a local connection subnet route, the gateway address is the IP address assigned to the subnet interface. A gateway address is a directly accessible IP address allocated to an adjacent router.

Metric

Specify the integer (range: 1 ~ 9999). It is used to select the route that best matches the destination address in the forwarding packet among multiple routes in the routing table. The selected route has the minimum number of hops. The number of hops reflects the quantity, speed, reliability, throughput, and management attributes of the hops.

If interface specifies the interface index of the interface that the target can reach. Use the Route print command to display the index list of the interface and its corresponding interface. The interface index can be in decimal or hexadecimal format. For hexadecimal values, add 0x before the hexadecimal number. When the if parameter is ignored, the interface is determined by the gateway address.

Note: the value in the number of hops column in the route table is large because TCP/IP is allowed to automatically determine the number of hops in the route table based on the IP address, subnet mask, and default gateway configuration of each LAN interface. By default, the auto-determine interface hops determine the speed of each interface and adjust the route hops of each interface. Therefore, the routes created by the fastest interface have the lowest hops. To delete the number of hops, disable automatic interface hops in the Advanced properties of the TCP/IP protocol for each LAN connection.

If an appropriate entry exists in the local network file of the systemrootSystem32DriversEtc folder, the name can be used for Destination. As long as the name can be resolved into an IP address through the standard host name resolution technology such as "Domain Name System" (DNS) query, it can be used for Gateway, and the DNS query is stored in systemrootSystem32DriversEtc

The local host file and NetBIOS name in the folder.

For the Print or Delete command, you can ignore the Gateway parameter and use wildcards to indicate the target and Gateway. The value of Destination can be a wildcard specified by the asterisk. If the specified target contains an asterisk (*) or question mark (?), It is regarded as a wildcard and only prints or deletes matched target routes. An asterisk represents a sequence of any character, and a question mark represents any character. For example, 10. *. 1, 192. 168. *, 127. *, and * 224 * are all effective use of the asterisk wildcard.

If an invalid combination of the target and subnet mask (netmask) values is used, "Route bad gateway address" is displayed.

Netmask "error message. This error occurs when one or more bits in the target are set to 1 and their corresponding bits in the subnet mask are set to 0. You can use binary notation to indicate the target and subnet mask to check this situation. The subnet mask in binary format includes a series of 1 representing the destination network address and a series of 0 representing the destination host address. Check whether some bits of the target host address (defined by the subnet mask) are set to 1.

This command is only available when TCP/IP is installed as a component of the network adapter attribute in a network connection.

Example:

Example 1: To display the complete content of the IP route table, run the following command:

Route print

Example 2: to display a route entry starting with 10 in the IP route table, run the following command:

Route print 10 .*

Example 3: to add a default route entry whose default gateway address is 192.168.12.1, run the following command:

Route add 0.0.0.0 mask 0.0.0.0 192.168.12.1

Example 4: to add a route entry whose destination is 10.41.0.0, whose subnet mask is 255.255.0.0, and whose next hop address is 10.27.0.1, run the following command:

Route add 10.41.0.0 mask 255.255.0.0 10.27.0.1

Example 5: to add a permanent route whose destination is 10.41.0.0, The subnet mask is 255.255.0.0, And the next hop address is 10.27.0.1, run the following command:

Route-p add 10.41.0.0 mask route 255.0.0 10.27.0.1

Example 6: to add a route entry with the target 10.41.0.0, subnet mask 255.0.0, Next Hop address 10.27.0.1, and number of hops 7, run the following command:

Route add 10.41.0.0 mask 255.255.0.0 10.27.0.1 metric 7

Example 7: to add a route entry whose destination is 10.41.0.0, whose subnet mask is 255.255.0.0, whose next hop address is 10.27.0.1, and whose interface index is 0x3, run the following command:

Route add 10.41.0.0 mask route 0.0 10.27.0.1 if 0x3

Example 8: to delete a route whose destination is 10.41.0.0 and the subnet mask is 255.255.0.0, run the following command:

Route delete 10.41.0.0 mask 255.255.0.0

Example 9: to delete all routes starting with 10 in the IP route table, run the following command:

Route delete 10 .*

Example 10: to change the next hop address of the route whose destination is 10.41.0.0 and whose subnet mask is 255.255.0.0 from 10.27.0.1 to 10.27.0.25, run the following command:

Route change 10.41.0.0 mask 255.255.0.0 10.27.0.25