3Com 10014298 Parameters are explained as follows IP address and mask, Deleting All Static Routes

86CHAPTER 5: IP ROUTING PROTOCOL OPERATION

The parameters are explained as follows:

■IP address and mask

The IP address and mask use a decimal format. Because the 1s in the 32-bit mask must be consecutive, the dotted decimal mask can also be replaced by the mask-length which refers to the digits of the consecutive 1s in the mask.

■Transmitting interface or next hop address

When you configure a static route, you can specify either the interface-type port-number to designate a transmitting interface, or the gateway-address to decide the next hop address, depending on the actual conditions.

You can specify the transmitting interfaces in the cases below:

■For the interface that supports resolution from the network address to the link layer address (such as the Ethernet interface that supports ARP), when ip-address and mask (or mask-length) specifies a host address, and this destination address is in the directly connected network, the transmitting interface can be specified.

■For a P2P interface, the address of the next hop defines the transmitting interface because the address of the opposite interface is the address of the next hop of the route.

In fact, for all routing items, the next hop address must be specified. When the IP layer transmits a packet, it first searches the matching route in the routing table, depending on the destination address of the packet. Only when the next hop address of the route is specified, can the link layer find the corresponding link layer address, and then forward the packet.

■For different configurations of preference-value, you can flexibly apply the routing management policy.

■The reject and blackhole attributes indicate the unreachable route and the blackhole route.

Configuring a Default Route

Perform the following configurations in system view.

Table 80 Configuring a Default Route

Operation	Command
Configure a default route	ip route-static0.0.0.0 { 0.0.0.0
	0 } { interface-name
	gateway-address } [ preference
	value ] [ reject blackhole ]
Delete a default route	undo ip route-static 0.0.0.0 {
	0.0.0.0 0 } { interface-name
	gateway-address } ]

Parameters for default route are the same as for static route.

Deleting All Static Routes

You can use the undo ip route-staticcommand to delete one static route. The Switch 7750 also provides the delete static-route all command for you to delete all static routes at one time, including the default routes.