Huawei Quidway NetEngine80E Configuration Manual page 817

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
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Issue 02 (2014-09-30)
NOTE
If the AS_Path information of a summarized route is lost, the AS_Path filter cannot be used to filter
the summarized route, but can still be used to filter the specific routes from which the summarized
route is derived.
An AS_Path filter can be used as a matching condition of a route-policy or be used in the
peer as-path-filter command.
1. Run:
system-view
The system view is displayed.
2. Run:
ip as-path-filter { as-path-filter-number | as-path-filter-name }
{ permit | deny } regular-expression
An AS_Path filter is configured.
NOTE
For details on how to use AS_Path filters, see
Expressions.
Configure a community filter.
A BGP community attribute is used to identify a group of routes with the same properties.
Routes can be classified by community attribute. This facilitates route management.
Some AS internal routes may not need to be advertised to any other AS, whereas AS external
routes need to be advertised to other ASs. These AS external routes have different prefixes
(as a result, an IP prefix list is inapplicable) and may come from different ASs (as a result,
an AS_Path filter is inapplicable). You can set a community attribute value for these AS
internal routes and another community attribute value for these AS external routes on an
ASBR to control and filter these routes.
1. Run:
system-view
The system view is displayed.
2. Run:
ip community-filter
A community filter is configured.
– To configure a standard community filter, run the ip community-filter { basic
comm-filter-name { permit | deny } [ community-number | aa:nn ]
basic-comm-filter-num { permit | deny } [ community-number | aa:nn ]
&<1-16> } [ internet | no-export-subconfed | no-advertise | no-export ]
command.
– To configure an advanced community filter, run the ip community-filter
{ advanced comm-filter-name | adv-comm-filter-num } { permit | deny } regular-
expression command.
Configure an extcommunity filter.
Similar to a BGP community filter, a BGP extcommunity filter is used to filter private
network routes.
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8 BGP Configuration
8.25 Applying BGP AS_Path Regular
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