6-6IP-Prefix ConfigurationIP-prefix plays a role similar to ACL and but is more flexible and easier to understand. When IP-prefix isapplied to filtering routing information, its matching object is the destination address information field ofrouting information.Configuration PrerequisitesBefore configuring a filter list, prepare the following data:z IP-prefix namez Range of addresses to be matchedConfiguring an ip-prefix listAn IP-prefix list is identified by its IP-prefix list name. Each IP-prefix list can comprise multiple entries.Each entry can independently specify a match range in the form of network prefix and is identified by anindex-number. For example, the following is an IP-prefix list named abcd:z ip ip-prefix abcd index 10 permit 1.0.0.0 8z ip ip-prefix abcd index 20 permit 2.0.0.0 8During the matching of a route, the router checks the entries in ascending order of index-number. Oncethe route matches an entry, the route passes the filtering of the IP-prefix list and no other entry will bematched.Follow these steps to configure an IPv4 IP-prefix list:To do... Use the command... RemarksEnter system view system-view —Configure an IPv4IP-prefix listip ip-prefix ip-prefix-name [ index index-number ]{ permit | deny } network len [ greater-equalgreater-equal | less-equal less-equal ]RequiredNot configured by defaultIf all the entries of the IP prefix list are in the deny mode, all routing information will be denied by thefilter. In this case, you are recommended to define an entry in the permit mode with the ip ip-prefixip-prefix-name index index-number permit 0.0.0.0 0 less-equal 32 command following multiple entriesin the deny mode to permit all the other IP routes.AS Path List ConfigurationA BGP routing information packet contains an AS path field. AS path list can be used to match the ASpath field in BGP routing information to filter out the routing information that does not match.Follow these steps to configure an AS path list:To do... Use the command... RemarksEnter system view system-view —
