• Apply a configured prefix list to incoming routes. You can specify an interface.If you enter the name of a non-existent prefix list, all routes are forwarded.CONFIG-ROUTER-OSPF modedistribute-list prefix-list-name in [interface]• Apply a configured prefix list to incoming routes. You can specify which type of routes are affected.If you enter the name of a non-existent prefix list, all routes are forwarded.CONFIG-ROUTER-OSPF modedistribute-list prefix-list-name out [connected | rip | static]Example of Viewing Configured Prefix Lists (ROUTER OSPF mode)To view the configuration, use the show config command in ROUTER OSPF mode, or the show running-config ospfcommand in EXEC mode.Dell(conf-router_ospf)#show config!router ospf 34network 10.2.1.1 255.255.255.255 area 0.0.0.1distribute-list prefix awe inDell(conf-router_ospf)#ACL ResequencingACL resequencing allows you to re-number the rules and remarks in an access or prefix list.The placement of rules within the list is critical because packets are matched against rules in sequential order. To order new rulesusing the current numbering scheme, use resequencing whenever there is no opportunity.For example, the following table contains some rules that are numbered in increments of 1. You cannot place new rules betweenthese packets, so apply resequencing to create numbering space, as shown in the second table. In the same example, applyresequencing if more than two rules must be placed between rules 7 and 10.You can resequence IPv4 and IPv6 ACLs, prefixes, and MAC ACLs. No CAM writes happen as a result of resequencing, so there is nopacket loss; the behavior is similar Hot-lock ACLs.NOTE: ACL resequencing does not affect the rules, remarks, or order in which they are applied. Resequencing merelyrenumbers the rules so that you can place new rules within the list as needed.Table 7. ACL ResequencingRules ResquencingRules Before Resequencing: seq 5 permit any host 1.1.1.1seq 6 permit any host 1.1.1.2seq 7 permit any host 1.1.1.3seq 10 permit any host 1.1.1.4Rules After Resequencing: seq 5 permit any host 1.1.1.1seq 10 permit any host 1.1.1.2seq 15 permit any host 1.1.1.3seq 20 permit any host 1.1.1.4Access Control Lists (ACLs) 101
