H3C Technologies H3C S7500E Series Switches - Manual (Page 27)

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z The network administrator can configure a default route with both destination and mask being
0.0.0.0. The router forwards any packet whose destination address fails to match any entry in the
routing table to the next hop of the default static route.
z Some dynamic routing protocols, such as OSPF, RIP and IS-IS, can also generate a default route.
For example, an upstream router running OSPF can generate a default route and advertise it to
other routers, which install the default route with the next hop being the upstream router.
Application Environment of Static Routing
Before configuring a static route, you need to know the following concepts:
1) Destination address and mask
In the ip route-static command, an IPv4 address is in dotted decimal format and a mask can be either
in dotted decimal format or in the form of mask length (the number of consecutive 1s in the mask).
2) Output interface and next hop address
While configuring a static route, you can specify either the output interface or the next hop address
depending on the specific occasion. The next hop address can not be a local interface IP address;
otherwise, the route configuration will not take effect.
In fact, each route lookup operation has to find the next hop to resolve the destination link layer
address
When specifying the output interface, note that:
z If the output interface is a Null 0 interface, there is no need to configure the next hop address.
z If you specify a broadcast interface (such as VLAN interface) as the output interface, you must
specify the corresponding next hop for the output interface.
3) Other attributes
You can configure different preferences for different static routes so that route management policies
can be applied more flexibly. For example, specifying the same preference for different routes to the
same destination enables load sharing, while specifying different preferences for these routes enables
route backup.
Configuring a Static Route
Configuration Prerequisites
Before configuring a static route, you need to finish the following tasks:
z Configure the physical parameters for related interfaces
z Configure the link-layer attributes for related interfaces
z Configure the IP addresses for related interfaces
Configuration Procedure
Follow these steps to configure a static route:
To do… Use the command… Remarks
Enter system view system-view —