Friday, March 25, 2011

- Dividing a Physical Interface intoSubinterfaces
- Routing Between VLANs
- Inter-VLAN routing using a router on a stick utilizes an externalrouter to pass traffic between VLANs.
- A router on a stick is configured with a subinterface for eachVLAN and 802.1Q trunk encapsulation

Redundancy in a hierarchical network:

As businesses become increasingly dependent on thenetwork, the availability of the network infrastructurebecomes a critical business concern.
- Redundancy is the solution for achieving the necessaryavailability.
- Layer 2 redundancy improves the availability of thenetwork by implementing alternate network paths byadding equipment and cabling.

1. The VLAN Management Challenge
- As the number of switches increases on a small- or medium-sized business network, the overalladministration required to manage VLANs and trunksbecomes a challenge.

2. Small Network VLAN Management
- The figure shows a network manager adding a newVLAN, VLAN30.
- The network manager needs to update the threetrunks to allow VLANs 10, 20, 30, and 99.
- Recall that a common error is forgetting to updatethe allowed list of VLANs on trunks.

3. Larger Network VLAN Management
- After you have manually updated this network a fewtimes, you may want to know if there is a way for theswitches to learn what the VLANs and trunks are so thatyou do not have to manually configure them.
- VLAN trunking protocol (VTP).

A VLAN allows a network administrator to create groupsof logically networked devicesthat act as if they are ontheir own independent network, even if theyshare acommon infrastructure with other VLANs.

- Using VLANs, you canlogically segment switchednetworks based onfunctions,departments, or project teams. - A VLAN is a logicallyseparate IP subnetwork.

Thursday, March 24, 2011

Segmentation allows network congestion to significantly reduced within each segment. 

- LAN Segmentation with Bridges.
- LAN Segmentation with Routers.

EIGRP (Enhanced Interior Gateway Routing Protocol)

1. Describe the background and history of EIGRP.
2. Describe the features and operations of EIGRP.
3. Examine the basic EIGRP configuration commands and identify their purposes.
4. Calculate the composite metric used by EIGRP.
5. Describe the concepts and operation of Dual.
6. Describe the uses of additional configuration commands of EIGRP.

Connecting to an Ethernet LAN Internetworking 1 Network Interface Card © 2007 Cisco Systems, Inc. All rights reserved. ICND1 v1.0²1-2 Digital Bandwidth The amount of data that could flow across a network segment in a given length of time. Determined by the properties of the medium and the technology used to transmit and detect signals.

Understanding TCP/IP Transport Layer Internetworking 1 Transport Layer Session multiplexing Segmentation Flow control (when required) Connection-oriented (when required) Reliability (when required) © 2007 Cisco Systems, Inc. All rights reserved.

Understanding TCP/IP Internet Layer Internet Protocol Characteristics Operates at network layer of OSI Connectionless protocol Packets treated independently Hierarchical addressing Best-effort delivery No data-recovery features © 2007 Cisco Systems, Inc. All rights reserved.

Understanding Host-to-Host Communications Model © 2007 Cisco Systems, Inc. All rights reserved. ICND1 v1.0²1-1 Why a Layered Network Model? Reduces complexity Standardizes interfaces Facilitates modular engineering Ensures interoperable technology Accelerates evolution Simplifies teaching and learning © 2007 Cisco Systems, Inc.

What is a Network?

A network is an interconnection of computers and network devices for the purpose of information interchange and resource sharing.


1. To provide you with the knowledge and skills necessary to install, operate, and troubleshoot a small network.

2.1 CCNA - Intro-to-Routing

Routing Protocols and Concepts:

•Describe the basic purpose of a router
–Computers that specialize in sending packets over the data network.
–They are responsible for interconnecting networks by selecting the best path for a packet to travel and forwarding packets to their destination
•Routers have many of the same hardware and software components that are found in other computers including:
–Operating System


Hello Packet Purposes:

1. Discover OSPF neighbors and establish adjacencies.
2. Advertise guidelines on which Routers must agree to become neighbors.
3. Use by multi-access networks to elect a designated router and a back-up designated router.