Command Reference Guide

3Com Router 3000 Ethernet Family
Command Reference Guide
Chapter 1 Static Route Configuration Commands
3Com Corporation
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Use the ip route-static vpn-instance command to configure a static route. In the
application of multi-role host, you can configure a static route on a private network to
specify the interface of another private network or public network as its outbound
interface.
Use the undo ip route-static vpn-instance command to remove the static route
configuration.
By default, the system can obtain the sub-net route directly connected with the router.
When configuring a static route, the default preference is 60 if it is not specified. If it is
not specified as reject or blackhole, the route will be reachable by default.
Precautions when configuring static route:
z When the destination IP address and the mask are both 0.0.0.0, it is the default
route. If it is failed to detect the routing table, a packet will be forwarded along the
default route.
z For different configuration of preference level, flexible routing management policy
can be adopted. For example, configure multiple routes to the same destination.
Load sharing can be fulfilled by specifying the same preference for the routes.
Route backup can be realized by specifying different preferences.
z To configure static route, either transmission interface or next hop address can be
specified, which one is adopted in practice depends on actual condition. For the
interfaces supporting the resolution from network address to link layer address or
point-to-point interface, transmission interface or next hop address can be
specified. But for NBMA interfaces, such as the interface or dialing interface
encapsulated with X.25 or frame-relay, they support point-to-multi-point. Except IP
route is configured, secondary route, i.e. the map from IP address to link layer
address should be established on link layer. In such condition, transmission
interface cannot be specified and the next hop IP address should be configured
when configuring static route.
z VT interface cannot be configured as outbound interface.
z In some conditions (for example, the link layer is encapsulated with PPP),
transmission interface can be specified when opposite address cannot be learned
in router configuration. After specifying transmission interface, the configuration of
this router is unnecessary to be modified as opposite address changes.
Related command: display ip routing-table.
Example
# Configure the next hop of the default route as 129.102.0.2.
[3Com ] ip route-static 0.0.0.0 0.0.0.0 129.102.0.2
# Configure the static route, whose destination address is 100.1.1.1 and whose
next-hop address is 1.1.1.2.