Configure IP Routing Policy 485
type is the type of ospf external route corresponding to the imported route when
ospf is importing other protocol routes. type 1 refers to external route type 1 and
type 2 refers to external route type 2.
The metric value of the imported route can be set as the following:
1Specify the metric value with the apply cost command.
2Filter the route with routing policy and set attributes for the route matching the
conditions.
3If neither of the above is specified, the imported route uses the default metric
value. The default metric can be specified with the default-med command.
When both routing policy and med value are specified, the routing information
matching the routing policy will use the metric specified by the apply command
of a routing policy.
Defining an IP Prefix List An IP prefix list is identified with the list name and consists of several parts, with
the sequence-number specifying the matching order of these parts. In each part,
you can specify an individual matching range in the form of network prefix.
It should be noted that:
■In the process of matching, different parts of different sequence-numbers use
Boolean “OR” operations and the routing information matches different parts
in turn. Matched with a specific part of the IP prefix list is considered as
successfully filter through this IP prefix list
Perform the following configurations in system view.
Tabl e 564 Define an IP Prefix List
By default, no IP prefix list is defined.
Configuring Route Filter In some cases, only the routing information that meets the condition should be
distributed or imported, to prevent the neighboring routers from receiving private
information of other routes. A prefix-list or access list in the route strategy is used
to filter the routing information.
Perform the following configurations in RIP view, OSPF view, or BGP view.
1Configure filtering route information received
Define a strategic rule and quote an ACL or prefix-list to filter the routing
information that does not meet the requirements when receiving routes. Specify
an IP prefix list through gateway keywords, filtering the address of the
information router to receive only the updating messages from specific
neighboring routers.
Operation Command
Define an IP prefix list ip ip-prefix prefix-list-name [
index index-number ] { permit | deny
} network/len [ greater-equal
ge-value ] [ less-equal le-value ]
Cancel an IP prefix list undo ip ip-prefix prefix-list-name [
index seq-number ] [ permit | deny ]