Figure
-
shows
the ip route 201.222.5.0 255.255.255.0 and null 0 command.
Note that this mask is a subnet mask with the ones on the left,
and not an access-list wildcard mask with the ones on the right.
The static route forwards traffic for network 201.222.5.0 to the
null interface, which drops it.
Consider the example shown in Figure
.
Valid traffic is allowed through the WAN cloud if it is destined
for the subnet where the network management station is located.
Traffic to the Class C network 201.222.5.0 is blocked before it
enters the WAN cloud. In Figure
,
access-list processing is avoided on the left router by routing
unwanted traffic to the null interface.
You do not wish to have traffic sent to network 201.222.5.0, so you set up a static route to the null interface.
The static route will always give you a
better path than any routing protocol will find. Then you route the
packet to nowhere and drop it.
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Lab
Activity |
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In this lab,
you will learn how to deny traffic to a
specific network by using a static route to
the null 0 interface. |
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