H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – Routing Protocol
H3C S7500 Series Ethernet Switches Chapter 7 IP Routing Policy Configuration
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7.2.2 Define an IP Prefix List
An ip-prefix (IP prefix list) is identified by name. Each ip-prefix can include multiple
items, and each item, identified by an index-number, can independently specify the
match range in network prefix form. Index-numbers specify the matching order of the
items in the ip-prefix.
Follow these steps to define an IP prefix list:
To do... Use the command... Remarks
Enter system view
system-view
—
Define an IP prefix
list
ip ip-prefix ip-prefix-name [ index
index-number ] { permit | deny } network
len [ greater-equal greater-equal |
less-equal less-equal ]*
Required
During a matching test, the router checks the items in the ascending order of their
index-numbers. Once an item is met, the ip-prefix filtering is passed and no other item
will be checked.
 Note:
Among the items defined in an IP prefix list, at least one item should be in permit
mode. The items in deny mode can be used to quickly filter out undesired routing
information. But if all the items are in deny mode, no route will pass the filter of the
IP-prefix list. Therefore, you need to define the permit 0.0.0.0 0 greater-equal 0
less-equal 32 item following multiple deny mode items to permit all other routes to
pass through.
7.2.3 Configuring an AS Path List
A BGP routing information packet contains an AS path field, which can be used to filter
out the routing information that does not match.
Perform the following configuration in system view.
Follow these steps to configure an AS path list:
To do... Use the command... Remarks
Enter system view
system-view
—
Configure an AS path list
ip as-path-acl acl-number { permit |
deny } as-regular-expression
Required