Operation Manual – IPv4 RoutingH3C S5500-EI Series Ethernet Switches Chapter 6 Routing Policy Configuration6-4TaskCreating a Routing PolicyDefining if-match Clauses for the Routing PolicyConfiguring a Routing PolicyDefining apply Clauses for the Routing Policy6.3 Defining Filtering Lists6.3.1 PrerequisitesBefore configuring this task, you need to decide on:z IP-prefix list namez Matching address rangez Extcommunity list sequence number6.3.2 Defining an IPv4 prefix ListIdentified by name, each IPv4 prefix list can comprise multiple items. Each itemspecifies a matching address range in the form of network prefix identified by indexnumber.During matching, the system compares the route to each item identified by indexnumber 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… RemarksEnter system view system-view —Define an IPv4prefix listip ip-prefix ip-prefix-name [ indexindex-number ] { permit | deny } ip-addressmask-length [ greater-equal min-mask-length ][ less-equal max-mask-length ]RequiredNotdefined bydefaultNote: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 denymode 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 and10.3.0.0/16, but allows other routes to pass.
