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 • 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 switchor 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…: • Port-based VLANs (layer-1 VLANs) • MAC-based VLANs (layer-2 VLANs) • IP-based VLANs(layer-3 VLANS) • 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 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
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