Huawei Quidway NetEngine80E Configuration Manual page 819

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
Issue 02 (2014-09-30)
NOTE
The NE80E/40E considers that each unmatched route fails to match the route-policy by default.
If more than one node is defined in a route-policy, at least one of them must be in permit mode.
3. (Optional) Perform the following operations as needed to configure if-match clauses
for current nodes of the route-policy.
if-match clauses are used to filter routes. If no if-match clause is specified, all routes
will match the node in the route-policy.
– To match an ACL, run the if-match acl { acl-number | acl-name } command.
– To match an IP prefix list, run the if-match ip-prefix ip-prefix-name command.
NOTE
The if-match acl and if-match ip-prefix commands cannot be used together in the same
node of a route-policy, because the latest configuration will override the previous one.
– To match the AS_Path attribute of BGP routes, run the if-match as-path-filter
{ as-path-filter-number | as-path-filter-name } &<1-16> command.
– To match the community attribute of BGP routes, run either of the following
commands:
– if-match community-filter { basic-comm-filter-num [ whole-match ] | adv-
comm-filter-num }
– if-match community-filter comm-filter-name [ whole-match ]
– To match the extended community attribute of BGP routes, run the if-match
extcommunity-filter { { basic-extcomm-filter-num | adv-extcomm-filter-num }
&<1-16> | basic-extcomm-filter-name | advanced-extcomm-filter-name }
command.
The operations in Step 3 can be performed in any order. A node may have multiple
if-match clauses or no if-match clause.
NOTE
The relationship between the if-match clauses in a node of a route-policy is "AND". A route
must match all the rules before the action defined by the apply clause is taken. For example,
if two if-match clauses (if-match acl 2003 and if-match as-path-filter 100) are defined in the
route-policy route-policy-example permit node 10 command, a route is considered to match
node 10 only when it matches the two if-match clauses.
4. (Optional) Perform the following operations as needed to configure apply clauses for
current nodes of the route-policy:
apply clauses can be used to set attributes for routes matching if-match clauses. If
this step is not performed, the attributes of routes matching if-match clauses keep
unchanged.
– To replace or add a specified AS number in the AS_Path attribute of a BGP route,
run the apply as-path { as-number-plain | as-number-dot } &<1-10> { additive
| overwrite } | none overwrite } command.
– To delete a specified BGP community attribute from a route, run the apply comm-
filter comm-filter-number delete command.
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&<1-16>
8 BGP Configuration
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