3com 3031 Instruccion De Instalación

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Configure route filtering

A route-policy can comprise multiple nodes. Each node is a unit for matching 
operation. The nodes are tested according to sequence-number.

Perform the following configuration in System View.

The argument permit specifies the matching mode for a defined node in the 
route-policy to be in permit mode. If a route satisfies all the if-match clauses of the 
node, it will pass the filtering of the node, and the apply clauses for the node will 
be executed without taking the test of the next node. If not, however, the route 
should take the test of the next node.

The deny argument specifies the matching mode for a defined node in the 
route-policy to be in deny mode. In this mode, the apply clauses will not be 
executed. If a route satisfies all the if-match clauses of the node, it will be denied 
by the node and will not take the test of the next node. If not, however, the route 
will take the test of the next node.

The nodes have the "OR" relationship. In other words, the router will test the 
route against the nodes in the route-policy in sequence, once a node is matched, 
the route-policy filtering will be passed.

By default, the route-policy is not defined.

Note: if multiple nodes are defined in a route-policy, at least one of them should 
be in permit mode. Apply the route-policy to filter routing information. If the 
routing information does not match any node, the routing information will be 
denied by the route-policy. If all the nodes in the route-policy are in deny mode, all 
routing information will be denied by the route-policy.

The if-match clauses define the matching rules. That is, the filtering conditions 
that the routing information should satisfy for passing the route-policy. The 
matching objects are some attributes of routing information.

Perform the following configuration in route-policy view.

Table 672   Defining a route-policy

Enter route policy view

route-policy route-policy-name { permit | deny } 
node { node-number }

Remove the specified 
route-policy

undo route-policy route-policy-name [ permit | 
deny | node node-number ]

Table 673   Definiing if-match conditions

Match the AS path domain of 
the BGP routing information. 

where acl-number is the as-path-acl-number

Cancel the matched AS path 
domain of the BGP routing 
information