Cisco Systems OL-14763-02 Introduction

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Cisco Active Network Abstraction VNE Reference Guide, Version 3.6 SP1
OL-14763-02
Introduction
This chapter introduces Virtual Network Elements (VNEs) and describes the types of information
available in this Guide. It includes the following sections:
• Introduction to VNEs, page 1
• Understanding the Tables, page 2
Introduction to VNEs
VNEs (Virtual Network Elements) are independent software processes that run on the Cisco ANA Unit
Servers. Each VNE is assigned to manage a single network element (NE) using the NE's management
interfaces (for example, SNMP and/or Telnet). The VNEs maintain a live model, or abstraction, of each
NE and the entire network.
As the VNE loads, it starts investigating the NE and automatically builds a live model of the NE,
including its physical and logical inventory, its configuration and its status. After modeling the NE, the
VNE begins negotiating with peer VNEs, which represent the peer NEs, in order to determine NE
connectivity and topology at different layers. This model of the network topology, NE state, and NE
inventory is constantly being updated by the VNEs, which track every change that occurs in the NEs and
the network.
The VNEs communicate between themselves to analyze end-to-end flows, which provide information
for root-cause and impact analysis, service path tracing, and more.