Dell Force10 MXL Blade MXL 10/40GbE Switch IO Module Configuration Guide - Page 88

www.dell.com | support.dell.com The following rules apply to prefix lists: • A prefix list without any permit or deny filters allows all routes. • An "implicit deny" is assumed (that is, the route is dropped) for all route prefixes that do not match a permit or deny filter in a configured prefix list. • After a route matches a filter, the filter's action is applied. No additional filters are applied to the route. Implementation Information In FTOS, prefix lists are used in processing routes for routing protocols (for example, router information protocol [RIP], open shortest path first [OSPF], and border gateway protocol [BGP]). Note: The MXL Switch platform does not support all protocols. It is important to know which protocol you are supporting prior to implementing prefix lists. Configuration Task List for Prefix Lists To configure a prefix list, you must use commands in PREFIX LIST, ROUTER RIP, ROUTER OSPF, and ROUTER BGP modes. You create the prefix list in PREFIX LIST mode, and assign that list to commands in ROUTER RIP, ROUTER OSPF, and ROUTER BGP modes. The following list includes the configuration tasks for prefix lists: • Configure a Prefix List • Use a Prefix List for Route Redistribution For a complete listing of all commands related to prefix lists, refer to the FTOS Command Line Interface Reference Guide. Configure a Prefix List To configure a prefix list, follow these steps, starting in CONFIGURATION mode: Step Command Syntax 1 ip prefix-list prefix-name 2 seq sequence-number {deny | permit} ip-prefix [ge min-prefix-length] [le max-prefix-length] Command Mode CONFIGURATION CONFIG-NPREFIXL Purpose Create a prefix list and assign it a unique name. You are in PREFIX LIST mode. Create a prefix list with a sequence number and a deny or permit action. The optional parameters are: • ge min-prefix-length: is the minimum prefix length to be matched (0 to 32). • le max-prefix-length: is the maximum prefix length to be matched (0 to 32). 86 | Access Control Lists (ACLs)