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 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