NetFlow 102 – FNF – Flexible NetFlow

Netflow configuration is different by platform and IOS version. Initially, Cisco IOS supported what is now known as “Traditional/Original Netflow(TNF)”, but newer versions of the IOS support “Flexible Netflow (FNF). Support for Traditional Netflow configuration is being dropped from neweer IOS versions, so if available, use Flexible Netflow configuration on …

DMVPN

1. DMVPN DMVPN – Dynamic Multipoint VPN is a technology that uses IPSec, mGRE and NHRP to provide a dynamic VPN infrastructure. DMVPN evolved in several phases as follows: DMVPN phase 1: Hub and Spoke – spokes only communicate via Hub DMVPN phase 2: Hub and spoke with spoke to …

How CEF works

1. Process Switching 1.1 How it works Network interface detects a new packet on the wire. The interface will receive the packet …

MPLS L3 VPN

This article assumes the “provider” network already has an IGP in place and that the LDP is configured to advertise label bindings …

IS-IS Mechanics – CLNP

1. ISO OSI Terminology ISO OSI term TCP/IP Equivalent End System Host Intermediate System Router Circuit Interface Area Area Domain Autonomous System …

IS-IS 101

1. Starting the routing process Starting IS-IS process requires a 2 step configuration: 1. In the global config 2. On the interfaces …

Cisco Enterprise Architecture

1. Hierarchical Model Cisco Enterprise Architecture is based on a hierarchical model that consists of: Access Layer: provides connectivity without compromising network integrity …

IPSec VPN 101

1. IPSec IPSec is a framework of open standars that offers security services to IP communication. When using IPSec you get the …

Linux Terminal Colors

1. Enabling colored output 1.1 ls –color In Linux, you use the ls command to display the contents of a folder. ls …

Linux File System Hierarchy

Linux File System Hierarchy is a reference that describes how the Linux Files System Hierarchy should look like. Currently, the FHS in …