Configuring Ip Routing Policy - 3Com 8807 Configuration Manual

394 C 34: IP R
HAPTER OUTING
Routing Policy
Application
Configuring IP
Routing Policy
Configuring a
Route-policy
P C
OLICY ONFIGURATION
An IP-prefix is identified by the IP-prefix name. Each IP-prefix can include multiple
list items, and each list item can independently specify the match range of the
network prefix forms and is identified with an index-number. The index-number
designates the matching check sequence in the IP-prefix.
During the matching, the router checks list items identified by the
sequence-number in the ascending order. Once a single list item meets the
condition, it means that it has passed the IP-prefix filtering and will not enter the
testing of the next list item.
AS-path
The AS-path list is only used in the BGP. The routing information packet of the BGP
includes an autonomous system path domain (During the process of routing
information exchanging of the BGP, the autonomous system paths the routing
information has passed through will be recorded in this domain). Targeting at the
AS path domain, the AS-path specifies the match condition.
Community-list
The community-list is only used in the BGP. The routing information packet of the
BGP includes a community attribute domain to identify a community. Targeting at
the community attribute, the community-list specifies the match condition.
Two routing policy applications are as follows:
When advertising/receiving routing information, the router filters the information
according to the route policy, and receives or advertises the routing information
which can meet the specified condition only.
When importing other routes detected by other routing protocol, the router only
imports the routing information, which can meet the specified condition only,
according to the route policy.
The routing policy configuration includes:
1 Filter configuration includes:
"Configuring a Route-policy"
■
"Configuring ip-prefix"
■
"Configuring the AS Path List"
■
"Configuring a Community Attribute List"
■
n
For the configuration of ACL, refer to the "QoS/ACL Operation" part of this
manual.
2 Applications of routing policies include:
"Applying Route Policy on Imported Routes"
■
"Applying Route Policy on Received or Advertised Routes"
■
A route-policy can comprise multiple nodes. Each node is a unit for matching
operation. The nodes will be tested against by node-number.