H3C S7500E Series Ethernet Switches Operation Manual

Operation Manual – IPv4 Routing
H3C S7500E Series Ethernet Switches Chapter 6 Routing Policy Configuration
6-4
Task
Creating a Routing Policy
Defining if-match Clauses for the Routing Policy
Configuring a Routing
Policy
Defining apply Clauses for the Routing Policy
6.3 Defining Filtering Lists
6.3.1 Prerequisites
Before configuring this task, you need to decide on:
z IP-prefix list name
z Matching address range
z Extcommunity list sequence number
6.3.2 Defining an IPv4 prefix List
Identified by name, each IPv4 prefix list can comprise multiple items. Each item
specifies a matching address range in the form of network prefix identified by index
number.
During matching, the system compares the route to each item identified by index
number in the ascending order. If one item matches, the route passes the IP-prefix list,
without needing to match against the next item.
Follow these steps to define an IPv4 prefix list:
To do… Use the command… Remarks
Enter system view
system-view
—
Define an IPv4 prefix
list
ip ip-prefix ip-prefix-name [ index
index-number ] { permit | deny }
ip-address mask-length [ greater-equal
min-mask-length ] [ less-equal
max-mask-length ]
Required
Not defined by
default
 Note:
If all items are set to the deny mode, no routes can pass the IPv4 prefix list. Therefore,
you need to define the permit 0.0.0.0 0 less-equal 32 item following multiple deny
mode items to allow other IPv4 routing information to pass.
For example, the following configuration filters routes 10.1.0.0/16, 10.2.0.0/16 and
10.3.0.0/16, but allows other routes to pass.