Ip-Prefix Configuration; Configuring An Ip-Prefix List - Huawei Quidway S3900 Series Operation Manual

Operation Manual – Routing Protocol
Quidway S3900 Series Ethernet Switches-Release 1510
Note:
A route-policy comprises multiple nodes. The relationship among the nodes in a
route-policy is "OR". As a result, the system examines the nodes in sequence, and
once the route passes a node in the route-policy, it will pass the matching test of
the route-policy without entering the test of the next node.
During the matching, the relationship among the if-match clauses for a
route-policy node is "AND". That is, a matching test against a node is successful
only when all the matching conditions specified by the if-match clauses in the
node are satisfied. If no if-match clauses are specified, all the routes will filter through the node.
A node can comprise no if-match clause or multiple if-match clauses.
Each node comprises a set of if-match and apply clauses. if-match clauses
define matching rules. apply clauses specify the actions performed after a
matching test against the node is successful, and the actions can be the attribute
settings of routing information.

5.4 ip-prefix Configuration

ip-prefix plays a role similar to ACL and but is more flexible and easier to understand.
When ip-prefix is applied to filtering routing information, its matching object is the
destination address information field of routing information.
5.4.1 Configuration Prerequisites
Before configuring a filter list, prepare the following data:
ip-prefix name
Range of addresses to be matched
Extended community attribute list number

5.4.2 Configuring an ip-prefix list

An ip-prefix list is identified by its ip-prefix list name. Each ip-prefix list can comprise
multiple items. Each item can independently specify a match range in the form of
network prefix and is identified by an index-number. For example, the following is an
ip-prefix list named abcd:
ip ip-prefix abcd index 10 permit 1.0.0.0 8
ip ip-prefix abcd index 20 permit 2.0.0.0 8
During the matching of a route, the router checks the items in the ascending order of
index-number. Once the route match an item, the route passes the filtering of the
ip-prefix list and no other item will be matched.
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Chapter 5 IP Routing Policy Configuration