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DES-7200 Configuration Guide Chapter 1 Protocol-Independent
Configuration
1-10
1.3.3 Route Filtering
Route filtering is the process to control the incoming/outgoing routes so that the
router only learns the necessary and predictable routes, and only advertise the
necessary and predictable routes to external trusted devices. The divulgence and
chaos of the routes may affect the running of the network. Particularly for telecom
operators and financial service networks, it is essential to configure route filtering.
1.3.3.1 Controlling Route Updating
Advertising
To prevent other routers or routing protocols from dynamically learning one or
more route message, you can configure the control over route updating
advertising to prevent the specified route update.
To prevent route updating advertising, execute the following commands in the
routing process configuration mode:
Command Function
DES-7200(config-router)# distribute-list
{[access-list-number | access-list-name] |
prefix prefix-list-name out [interface-type
interface-number]
According to ACL rules, permit or deny
some routes.
Prefix: This keyword specifies the
prefix list for filtering routes. The prefix
list should be separately configured by
using the ip prefix-list command.
DES-7200(config-router)# no distribute-list
{[access-list-number | access-list-name]
| prefix prefix-list-name} out [interface-type
interface-number | protocol]
Remove the configuration.
Note
When you configure the OSPF, you cannot specify the interface and the
features are only applicable to the external routes of the OSPF routing area.
1.3.3.2 Controlling Route Updating
processing
To avoid processing some specified routes of the incoming route update packets,
you can configure this feature. This feature does not apply to the OSPF routing
protocol.
To control route updating processing, execute the following commands in the
routing process configuration mode: