Ex4 Chapter 6 - Telework Services

Teleworking is a broad term referring to conducting work by connecting to a workplace from a remote location, with the assistance of telecommunications.

Troubleshooting a serial interface

The show interface serial command returns one of five possible states. You can identify any of the following five possible problem states in the interface status line:

Ex4 Chapter 5 - ACLs

Ex4 Chapter 3 - Frame Relay

Ex4 Chapter 4 - Network Security

When discussing network security, three common factors are vulnerability, threat, and attack.
Vulnerability is the degree of weakness which is inherent in every network and device. This includes routers, switches, desktops, servers, and even security devices.
Threats are the people interested and qualified in taking advantage of each security weakness. Such individuals can be expected to continually search for new exploits and weaknesses.

Ex4 Chapter 2 - PPP

Ex4 Chapter 1 - Introduction to WANs

A WAN is a data communications network that operates beyond the geographic scope of a LAN.

Here are the three major characteristics of WANs:
 - WANs generally connect devices that are separated by a broader geographical area than can be served by a LAN.
 - WANs use the services of carriers, such as telephone companies, cable companies, satellite systems, and network providers.
 - WANs use serial connections of various types to provide access to bandwidth over large geographic areas.

Using Traceroute

Traceroute is the program that shows you the route over the network between two systems, listing all the intermediate routers a connection must pass through to get to its destination. It can help you determine why your connections to a given server might be poor, and can often help you figure out where exactly the problem is. It also shows you how systems are connected to each other, letting you see how your ISP connects to the Internet as well as how the target system is connected.
This tutorial was written for users of premium Usenet services, but can be useful for anyone wanting to learn to use traceroute.

Understanding TCP Sequence and Acknowledgment Numbers

http://packetlife.net/blog/2010/jun/7/understanding-tcp-sequence-acknowledgment-numbers/


PDF VERSION

If you're reading this, odds are that you're already familiar with TCP's infamous "three-way handshake," or "SYN, SYN/ACK, ACK." Unfortunately, that's where TCP education ends for many networkers. Despite its age, TCP is a relatively complex protocol and well worth knowing intimately. This article aims to help you become more comfortable examining TCP sequence and acknowledgment numbers in the Wireshark packet analyzer.

Ex3 Chapter 1 - LAN Design

Hierarchical network design (Cisco) model involves dividing the network into discrete layers. Each layer provides specific functions that define its role within the overall network.
The typical hierarchical design model is broken up in to three layers:
 - access,
 - distribution,
 - core.

Ex2 after practice exam

Thing to repeat and remeber:

Habits of Highly Effective Students

"What is the best way to study for a Certification Exam?"

This is probably the most common question I get asked by Network Academy  students and peers chasing Cisco Certifications. While there is no concrete answer that works for everyone, there are some really great pieces of advice that I have heard throughout the years, and implemented in my daily study routine.

Ex2 Chapter 12 – BGP basics

The Border Gateway Protocol (BGP) is the core routing protocol of the Internet. It maintains a table of IP networks or 'prefixes' which designate network reachability among autonomous systems (AS). It is described as a path vector protocol. BGP does not use traditional Interior Gateway Protocol (IGP) metrics, but makes routing decisions based on path, network policies and/or rulesets.

Routers use “routing protocols” to exchange routing information with each other.

Ex2 Chapter 11 – OSPF

Ex2 Chapter 10 – Link-State Routing Protocols

Distance vector routing protocols are like road signs because routers must make preferred path decisions based on a distance or metric to a network.
Link-state routing protocols take a different approach. Link-state routing protocols are more like a road map because they create a topological map of the network and each router uses this map to determine the shortest path to each network.

Ex2 Chapter 9 – EIGRP

Ex2 Chapter 7 – RIP version 2

The routing algorithm used in RIP, the Bellman-Ford algorithm, was first deployed in a computer network in 1967, as the initial routing algorithm of the ARPANET.Due to the deficiencies of the original RIP specification, RIP version 2 (RIPv2) was developed in 1993 and last standardized in 1998 It included the ability to carry subnet information, thus supporting Classless Inter-Domain Routing (CIDR). To maintain backward compatibility, the hop count limit of 15 remained. RIPv2 has facilities to fully interoperate with the earlier specification if all Must Be Zero protocol fields in the RIPv1 messages are properly specified. In addition, a compatibility switch feature allows fine-grained interoperability adjustments.

Ex2 Chapter 6 - Classful/classless, CIDR and FLSM/VLSM

Ex2 Chapter 5 – RIP version 1

RIP – Routing Information Protocol

RIP is the oldest routing protocol still in use today.  It is available on many platforms and is not a protocol that will be deprecated anytime soon.  It is a useful protocol for networks that are large enough for a routing protocol but not large enough for some of the more powerful and expensive protocols available.  RIP even has a new RIPng version to handle IPv6 networks.

Ex2 Chapter 4 – Distance Vector Routing Protocols

Ex2 Chapter 3 - Introduction to Dynamic Routing

Ex2 Chapter 2 - Static Routing, CDP

Role of Router
1.  Determine best path to send packets.
2.  Forward packets toward their destinations.

Ex2 Chapter 1 - Introduction to Routing and Packet Forwarding

Static and Dynamic Routing
Routers know of networks that are only directly connected to them.  Obviously, routers need some method of learning about distant networks they need to access.  There are two methods of learning about these distant networks, static and dynamic route learning. Static routes are when an administrator adds specific network routes to a router or multiple routers.