Huawei Quidway S3500 Series Operation Manual page 253

Operation Manual - Routing Protocol
Quidway S3500 Series Ethernet Switches
For routing information filtering, the basic ACL is generally used. When the user defines
the ACL, he will define the range of an IP address or subnet to the destination network
segment address or the next-hop address of the routing information. If an advanced
ACL is used, perform the matching operation by the specified source address range.
For the configuration related to acl, refer to the QoS/ACL Operation Manual and
Command Manual contained in the security section of this manual.
III. ip-prefix
The function of the ip-prefix is similar to that of the acl, but it is more flexible and easy
for the users to understand. When the ip-prefix is applied to the routing information
filtering, its matching objects are the destination address information domain of the
routing information, and furthermore, in the ip-prefix, the users can specify the gateway
options and specify it to receive only the routing information distributed by some certain
routers.
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.
IV. as-path list
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.
The definition of the as-path has already been implemented in the BGP configuration.
For the related configurations, please refer to the ip as-path-acl command in the BGP
Configuration.
V. 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.
The definition of the community-list has already been implemented in the BGP
configuration. For the relevant configurations, please refer to the ip community-list
command in the BGP Configuration.
Huawei Technologies Proprietary
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Chapter 6 IP Routing Policy Configuration