CCNP Large Scale BGP: AS-Path ACL, Regular expressions (regex): GNS3 CCNP Lab 1.6: Answers Part 7

GNS3 Portable Project File: https://bit.ly/2JjtYh6 This is one of multiple Cisco CCNP GNS3 Labs. Are you ready to pass your CCNP exam? For lots more content, visit http://www.davidbombal.com - learn about GNS3, CCNA, Packet Tracer, Python, Ansible and much, much more. 300-101 ROUTE Exam information: https://bit.ly/2GkcFXQ 300-115 SWITCH Exam information: https://bit.ly/2KrSWIe 300-135 TSHOOT Exam information: https://bit.ly/2IlHpgY Training: http://www.davidbombal.com AS-path Access list: ACL ip as-path access-list To configure an access-list filter for Border Gateway Protocol (BGP) autonomous system (AS) numbers, use the ip as-path access-list command. To remove the filter, use the no form of this command. ip as-path access-list name { deny | permit } regexp no ip as-path access-list name { deny | permit } regexp Regex: A regular expression is entered as part of a command and is a pattern made up of symbols, letters, and numbers that represent an input string for matching (or sometimes not matching). Matching the string to the specified pattern is called pattern matching. Pattern matching either succeeds or fails. If a regular expression can match two different parts of an input string, it will match the earliest part first. Cisco configurations uses regular expression pattern matching in several implementations Route Filtering and Manipulation Route filtering is a method for selectively identifying routes that are advertised or received from neighbor routers. Route filtering may be used to manipulate traffic flows, reduce memory utilization, or to improve security. For example, it is common for ISPs to deploy route filters on BGP peerings to customers. Ensuring that only the customer routes are allowed over the peering link prevents the customer from accidentally becoming a transit AS on the Internet. Filtering of routes within BGP is accomplished with filter-lists, prefix-lists, or route-maps on IOS and NX-OS devices. Border Gateway Protocol (BGP)