VLANs

Virtual Local Area Networks

BA 479

Who are we? Ryan Winklepleck

Senior, Business, MIS, this ‘boy wonder’ is 21-years-old and still figuring out post-college life, possibly the circus is hiring?

Kameel Husain Senior, Business, MIS, would like to work with graphic designs

and databases. Likes milk, bones are as strong as antimantium, cage fighter.

Rob Jerand Senior, Business, MIS, always up for kegstands and dollar

beers, enjoys running from the Cops, giving beer cans to the bums, and my future consists of either being a janitor at Microsoft, or live in my parent’s basement and do nothing.

Andrew Grill Jr. III Bats: R, Throws: R, Avg: .405, RBI: 132, HR: 59, Triple Crown

MVP, after a gamma blast accident, you don’t want to see him when he’s angry. Business, MIS, accounting intern at weyerhaeuser and plans to work there in the future.

VLAN - Brief Introduction

Five W’s and an H…

VLAN Introduction

What? “Networks in which computers are assigned to LAN

segments by software rather than by hardware.” Who?

Us Why?

Often faster, while providing greater opportunities to manage the flow of traffic on the LAN and Backbone Network (BN) in comparison to traditional LAN and routed BN architectures.

VLAN Introduction

Where? Hosting Centers and Ethernet Metropolitan

Area Network (MAN)

When? Due to their complexity, usually only used for

large networks.

And the H…

VLAN History

Thought it was going to be How?

VLAN History

First Products: Segmentable Switches Allows creation of two or more virtual

switches from a single switch. Assigning individual ports to a specific virtual

switch. First products allowed switching of multiple

segments on a single switch, as well as offering a monetary advantage over switched Ethernet ports which cost $700 or more at the time.

VLAN Background

However, VLAN Backwards would be NALV…

VLAN Background

Local Area Networks (LAN) Generally defined as a broadcast domain. “Hubs, bridges, or switches on the same physical

segment or segments connect end node devices” A router is not needed for end nodes on the same

LAN segment to communicate with each other. However a router is necessary for these devices to

communicate with devices on other LAN segments.

VLAN Background

To the left, a LAN environment connected by routers

Drawback: Routers add latency

that delays the transmission of data

Solution? Switched Network

VLAN Background

To the right, a LAN environment connected by switches. Speed and latency

advantages. Drawback:

All end nodes (or hosts) are in same broadcast domain, which adds to the network a significant amount of traffic that is seen by all hosts.

Solution? Switched Network w/VLANs

Single-Switch VLAN

Single-Switch VLAN

The VLAN operates only inside one switch.

Computers, dozens or even hundreds, on the VLAN are connected into this switch and assigned by software into different VLAN segments.

VLAN segments act as though they are connected to the same physical switch or hub.

Single-Switch VLAN cont.

It’s possible to have one computer only in a VLAN. (Servers)

Four ways in which computers attached to a VLAN can be assigned to specific VLANs inside them …:

1. Port-based VLANs (layer-1 VLANs)

2. MAC-based VLANs (layer-2 VLANs)

3. IP-based VLANs (layer-3 VLANS)

4. Application-based VLANs (layer-4 or policy-based VLANS)

Port-based VLANs (layer-1 VLANs)

Uses physical layer port number on the front of the VLAN switch to assign computers to VLAN segments.

All computers are physically cabled into a specific port on the VLAN switch.

A software is used to instruct the switch as to which ports are assigned to which VLAN.

MAC-based VLANs (layer-2 VLANs)

Uses data link layer address or physical address to form VLANs.

A software is used to instruct the switch as to which incoming data link layer addresses are assigned to which VLAN segment.

Easier to manage than Port-based.

Multi-Switch VLAN

Multi Switch Approach

Layer 3 Layer 4 IEEE 802.1Q

Layer 3

Network layer

serves as the backbone for network traffic going across different VLANs.

provides logical routing interfaces to VLANs on Layer 2 switches. A traditional network requires a physical interface from a router to a switch to perform inter VLAN routing.

Layer 4

Transport Layer

Decides on where to send the packets. sends incoming packets to one or more

machines which are hidden behind a single IP address.

IEEE 802.1Q

allows multiple bridged networks to transparently share the same physical network link without leaking information

VLAN Benefits

What is Yreka Bakery spelled backwards?

Benefits

Performance VLANs can reduce sending traffic to unnecessary destinations

Formation of Virtual Workgroups Segment sections of business (marketing, accounting, etc) by

VLAN Drawback – distance in physical location, centralized server

farms

Simplified Administration Adding, changing, moving user accounts no new

reconfiguration of hubs/routers necessary

Benefits

Reduce Costs VLANs can be used to create broadcast domains which can

eliminate cost of expensive routers

Security Keep information restricted to only users who need access Can control boadcast domains, set up firewalls and more

VLAN Drawbacks

Drawbacks

Costs Purchasing additional hardware May need to hire new employee to manage

Misc. New users may encounter new problems they are not familiar

with If users are located on different floors of a building common

resources (such as a printer) could be in inconvenient locations