H3C S5120-SI Series, Руководство по эксплуатации

Страница: 266 / 697

1-2
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 digits 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, all the route entries must have a next hop address. When forwarding a packet, a router first
searches the routing table for the route to the destination address of the packet. The system can find the
corresponding link layer address and forward the packet only after the next hop address is specified.
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 a 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 —
Configure a static
route
ip route-static dest-address { mask | mask-length }
{ next-hop-address | interface-type interface-number
next-hop-address } [ preference preference-value ]
[ description description-text ]
Required
By default,
preference for
static routes is 60,
tag is 0, and no
description
information is
configured.