3com 3.01.01 User Manual

C

HAPTER

 5: IP R

OUTING

 P

ROTOCOL

 O

PERATION

entry of the routing table, the router selects the default route to forward this 
packet. If there is no default route and the destination address of the packet fails 
to match any entry in the routing table, the packet is discarded, and an Internet 
Control Message Protocol (ICMP) packet is sent to the originating host to indicate 
that the destination host or network is unreachable.

In a typical network that consists of hundreds of routers, if you used multiple 
dynamic routing protocols without configuring a default route then significant 
bandwidth would be consumed. Using the default route can provide appropriate 
bandwidth, but not high bandwidth, for communications between large numbers 
of users.

Configuring Static Routes is described in the following sections:

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Static route configuration tasks are described in the following sections:

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Perform the following configurations in system view.

The parameters are explained as follows:

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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.

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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:

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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 

Table 2   Configuring a Static Route

Add a static route

ip route-static ip-address {mask | 
mask-length } { interface-name | 
gateway-address } [ preference value ] [ 
reject | blackhole ]

Delete a static route

undo ip route-static ip-address {mask | 
mask-length } { interface-name | 
gateway-address} [ preference value ]