Flexible NetFlow—Ingress VRF Support Overview The Flexible NetFlow—Ingress VRF Support feature enables collecting the virtual routing and forwarding (VRF) ID from incoming packets on a device by applying an input flow monitor having a flow record that collects the VRF ID as a key field. Flexible Netflow—Egress VRF Support Overview The Flexible Netflow—Egress VRF Support feature enables collecting the VRF ID from outgoing packets on a device by applying an output flow monitor having a flow record that collects the VRF ID as a key field.
Autonomous System Number The Autonomous System number space is a 32 bit field with 4,294,967,296 unique values, which are available for use to support the Internet's public inter-domain routing system. An Autonomous System Number (AS number) is a special number assigned by IANA, used primarily with Border Gateway Protocol. It uniquely identifies a network under a single technical administration that has a unique routing policy, or is multi-homed to the public internet. This autonomous system number is required to run BGP and peer with your internet service provider, between internet service providers at peering points, and Internet Exchanges (IX).
The AS number must be globally unique so that IP address blocks appear to come from a unique location that BGP can find and route to. BGP uses Prefixes and Autonomous System Paths (AS Paths) to determine the shortest path to a destination where a prefix is located. NetFlow V9 and IPFIX export types support 32 bit AS number. NetFlow Version 5 export protocol supports the 32 AS field. The exported field contains the lower 32 bits of the 64 bit counter value. You can export the below BGP parameters in Netflow: • BGP source origin or peer AS number • BGP destination origin or peer AS number Configuration Use the below command to configure AS number system:
[no] collect routing { destination | source } as [[4-octet] peer] [4-octet] Ingress Egress Flexible NetFlow on MPLS Overview • Ingress Flexible Netflow on MPLS (IP level): This feature allows the capture of Internet Protocol (IP) flow information for packets undergoing MPLS label imposition that are entering the MPLS network. These packets arrive on a router as IP packets and are transmitted as MPLS packets. This feature can be enabled by configuring an ingress flow monitor for IPv4 and IPv6 traffic at the CE facing side of the PE node. • Egress Flexible NetFlow on MPLS (IP level):
This feature allows the capture of Internet Protocol (IP) flow information for packets undergoing MPLS label imposition that are exiting the MPLS network. These packets arrive on a router as MPLS packets and are transmitted as IP packets. The feature can be enabled by configuring an egress flow monitor for IPv4 and IPv6 traffic at the CE facing side of PE node. Configuring Flexible NetFlow Flexible NetFlow—Ingress VRF Support Overview Configuring Flexible NetFlow 19