Blackhole route: route with blackhole attribute. If a static route destined for a destination has the
blackhole attribute, the outgoing interface of this route is the Null 0 interface regardless of the next
hop address, and all the IP packets addressed to this destination will be dropped without notifying
the source hosts.
The attributes reject and blackhole are usually used to limit the range of the destinations this router
can reach, and help troubleshoot the network.
Default Route
To avoid too large a routing table, you can configure a default route.
When the destination address of a packet fails to match any entry in the routing table,
If there is default route in the routing table, the default route will be selected to forward the packet.
If there is no default route, the packet will be discarded and an ICMP Destination Unreachable or
Network Unreachable packet will be returned to the source.
A default route can be manually configured or generated by some dynamic routing protocols, such as
OSPF and RIP.
Static Route Configuration
Configuration Prerequisites
Before configuring a static route, perform the following tasks:
Configuring the physical parameters of related interfaces
Configuring IP addresses for related interfaces
Configuring a Static Route
Follow these steps to configure a static route:
To do...
Enter system view
Configure a static
route
Use the command...
system-view
ip route-static ip-address { mask |
mask-length } { interface-type
interface-number | next-hop } [ preference
preference-value ] [ reject | blackhole ]
[ detect-group group number ] [ description
text ]
2-2
Remarks
—
Required
By default, the system
can obtain the route to the
subnet directly connected
to the router.