Virtual Private Networks (VPNs)
There are two types of VPN:
- Site-to-site: connect networks together
- Remote access (Cisco Easy VPN, Cisco IOS IPSec SSL VPN [Web VPN]): connect individual hosts to corporate network
IPSec is a framework that allows choices of many protocols depending on the features required. IPSec provides:
- Confidentiality: ensures only authorized devices can read the data sent
- Integrity: ensures data is not changed during transmission
- Authentication: ensures communicating with an authorized device
- Anti-replay protection: verifies that each packet is unique and has not been duplicated
IOS Command Line Interface (CLI) and Commands
- In each of the tables in the downloadable white paper the commands are listed in alphabetical order.
- Many of the commands can be used on routers and switches.
- Most commands have many parameters. In the tables only a few of the parameters are shown. Refer to the Command Reference documentation on Cisco’s web site for the full command syntax.
IOS EXEC Operating Modes
Copy new IOS and configuration file to device
|Privileged||Router#||Full privileges to read, write, modify, copy, and delete|
|Configuration||Router(config)#||Modify the active (running) configuration file|
|Core||To move network traffic as fast as possible||
|Distribution||Perform packet manipulation such as filtering, routing, and redistribution between different routing protocols||
|Access||Where end-stations are connected to the network||
Cisco IOS Filenames and Packaging
Cisco IOS Filename Structure
IOS filenames are of the format:
Architecture: c2800 is a 2800 series device
Feature Set: ipbase is Entry level Cisco IOS Software image
Packaging: mz is run from ram and compressed file
Version: major minor – revision; 124-5a is Major release 12, Minor release 4 revision 5a
Type:file type; bin is binary file type
Cisco IOS Software Lifecycle Definitions
- First Commercial Shipment (FCS) — The initial version of a software release, which delivers new functionality to the marketplace.
- CCO FCS Date — The date at which the software release is commercially available to customers for electronic download from Cisco Connection Online (CCO). Typically occurs one week prior to MFG FCS.
- MFG FCS Date — The date at which the software release is commercially available to customers from Cisco manufacturing.
- Product Bulletin# — The ID of the Product Bulletin which describes the new features in the software release.
- Major Release — A Major Release of Cisco IOS software delivers a significant set of platform and feature support to market. No new features, platform or interface support are added to a Major Release after its initial FCS to protect the stability of the release.
- General Deployment (GD) — A Major Release of Cisco IOS software reaches the “General Deployment” milestone when Cisco feels it is suitable for deployment anywhere in customer networks where the features and functionality of the release are required. Criteria for reaching the “General Deployment” milestone are based on, but not limited to, customer feedback surveys from production and test networks using the releases, CE bug reports, and reported field experience. Only Major Releases are candidates to reach the General Deployment milestone.
- Limited Deployment (LD) — A Major Release of Cisco IOS software is said to be in the “Limited
Deployment” phase of its lifecycle during the period between initial FCS and the General Deployment (GD) milestones.
- GD Release — The maintenance release at which the major release reached the “General Deployment” milestone in its lifecycle. For example, Cisco IOS Release10.0 became “GD” on 01/03/95 with the availability of maintenance release 10.0(7).
- Early Deployment (ED) Release — Offer new feature, platform or interface support.
- End of Sales — After this date, the software release may no longer be ordered. Releases which reach this milestone are still available through FSO and CCO for customers under maintenance contract or for Customer Service Engineering (CSE) support until they reach the “End of Life” milestone.
- End of Engineering/Software Maintenance — The date after which no scheduled maintenance releases will be produced for the major release. Releases which reach this milestone are still available through FSO and CCO for customers under maintenance contract or for CSE support until they reach the “End of Life” milestone.
- End of Life/Last Date of Support — After this date, the software release is no longer officially supported by CSE and is removed from CCO. Note: Cisco IOS software releases typically reach the “End of Life” milestone three years following FCS of the major release. Specific “End of Life” dates are determined on a case-by-case basis.
- Obsolete — After this date, the maintenance release is no longer orderable and is removed from CCO. The term “obsolete” generally refers to a maintenance release within a major release train.
Excerpted and available for download from Global Knowledge White Paper: CCNA v1.1 Exam Review: Critical Concepts of the 640 – 802 CCNA Exam