VLAN History

hellhollowreadingNetworking and Communications

Oct 26, 2013 (3 years and 9 months ago)

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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


W
hat?


“Networks in which computers are assigned to LAN
segments by software rather than by hardware.”


W
ho?


Us


W
hy?


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


W
here?


Hosting Centers and Ethernet Metropolitan
Area Network (MAN)


W
hen?


Due to their complexity, usually only used for
large networks.


And the
H


VLAN
H
istory

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
802.1
Q


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