3Com Switch 7754, Configuration Manual

Page: 379 / 940

IP Routing Policy Configuration 379
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Refer to “ACL Configuration” on page 637.
2 You can have routing policy applied in the following cases:
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When routes are imported
■
When routes are advertised/received
Configuring a
Route-Policy
A route-policy can comprise multiple nodes. Each node is a unit for matching test,
and the nodes will be matched in the order of their sequence numbers.
Each node comprises a set of if-match and apply clauses.
■
The if-match clauses define the matching rules. The relationship among the
if-match clauses in a node is logical “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.
■
The apply clauses specify the actions performed after a matching test against
the node is successful, and the actions can be the setting of route attributes.
Defining a route-policy
The permit argument specifies that the matching mode for the defined node in
the route-policy is “permit”. In this mode, if a route matches all the if-match
clauses of the node, the system considers that the route passes the filter of the
node and then executes the
apply clauses of the node and does not take the test
of the next node. If not, the system goes on the test of the next node.
The deny argument specifies that the matching mode for the defined node in the
route-policy is “deny”. In this mode, no apply clause is executed. If a route
satisfies all the if-match clauses of the node, the system considers that the route
fails to pass through the node and does not take the test of the next node. If not,
the system goes on the test of the next node.
The relationships among different nodes in a route-policy are logical “OR”. As a
result, the system examines the nodes in the route-policy in sequence for a route,
and once the route passes a node in the route-policy, it passes the filter of the
whole route-policy without going on the test of the next node.
By default, no route-policy is defined.
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Among the nodes defined in a route-policy, at least one node should be in permit
mode. When a route-policy is applied to filtering routing information, if a piece of
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.
Table 308 Define a route-policy
Operation Command Description
Enter system view system-view -
Define a route-policy and
enter the route-policy
view route-policy route-policy-name { permit |
deny } node node-number
Required