Configuring IEEE 802.1Q Tunneling, VLAN Mapping, 802.1ad ...
Session #: 7061 Dwight Reifsnyder Virtual LANS. Session #: 706 Whats the Point? Why Bother? IEEE...
-
Upload
gustavo-freeny -
Category
Documents
-
view
214 -
download
1
Transcript of Session #: 7061 Dwight Reifsnyder Virtual LANS. Session #: 706 Whats the Point? Why Bother? IEEE...
1 Session #: 706
Dwight Reifsnyder
Virtual LANS
Session #: 706
What’s the Point? Why Bother?
“IEEE 802.1Q tagging (VLAN) is a useful method of managing VoIP traffic in your
LAN.
Avaya recommends that you establish a voice VLAN, set L2QVLAN to that VLAN and provide voice traffic with priority over
other traffic.”IP Phones LAN Admin Guide, Feb 2007
3Session #: 706
EYAWTK – Session Overview
• Provide a basic understanding of VLANS
• Discuss IP phone VLAN implementation
• We might accidentally learn some other useful information if we are not careful
Session #: 706
Broadway Suites
• Service Provider for downtown Boulder office buildings, including Executive Suites
• Multiple, diverse businesses in one space• Fortune 500 services on a small company
budget
Session #: 706
Broadway Suites
6Session #: 706
What is a Virtual LAN?
• A virtual LAN, commonly known as a VLAN, is a method of creating independent logical networks within a physical network.
• Virtual LANs operate at Layer 2 (the data link layer) of the OSI model.
Wikipedia
Session #: 706
Background – The 7 layer burrito
OSI Model
Squishy, not specific
VLANs are in Layer 2
Session #: 706
What Lives at Layer 2?
• Software – Ethernet Protocol
• End Points• Ethernet Hubs• Ethernet Switches
Session #: 706
L2 Hardware – Endpoints
• Phones and PCs are multi layer devices
• We will talk about them at layer 2 today
Session #: 706
L2 Hardware – Network Hub
• Network Hubs – • broadcast traffic• not very efficient
Session #: 706
L2 Hardware – Network Switch
• Network Switches –• Starts like a hub• Gradually directs traffic
to specific ports instead of broadcast
• How do they do that?
Session #: 706
Detour - L2 MAC Addresses
• Like a VIN Number on a car
• Unique to each and every network device
00-07-E9-55-64-4D
• MAC addresses are used to identify the sender and recipient of an ethernet packet
Session #: 706
Network Switch
• Stores MAC addresses and associated port numbers in a table
• Makes network more efficient!
Session #: 706
Evolution - Managed Switches
Have a user console that can show -• If a port is connected or not• Port speed (10MB, 100MB, 1000MB)• MAC address table• Calls out with alarms
• Best solution for Administrators• Cost more $$$$$!
Session #: 706
Segregation – Sorry Dr. King..
• Sometimes we need to have departments separated – • HR, confidentiality• Marketing, high bandwidth usage• Operations
• Each department needs its own LAN
Session #: 706
Segregation – The Old Way
• Multiple Managed Network Switches
• Costly • Complex
Session #: 706
Segregation – The New Idea
• Multiple MAC Address Tables
• One switch, divided into 'Virtual LANs‘
• Great idea, how would it work?
Session #: 706
Detour - RFCs (secret recipes)
• Request for Comments
• Internet Engineering Task Force (IETF)
• Institute of Electrical and Electronics Engineers (IEEE)
Session #: 706
Some Common RFCs
802.1a,b,g,etc Wireless Ethernet (WiFi)
854 Telnet
802.1x Network Access Control
1719 Private Class IP numbers
821 SMTP (Simple Mail Transport Protocol)
1939 POP3 (Post Office Protocol 3)
802.3AF Power Over Ethernet
2131 DHCP (Dynamic Host Configuration)
Session #: 706
RFC 802.1q - VLANs
• Defines how to segregate a single L2 network switch into multiple “virtual' LANs or networks with multiple MAC tables
• One managed network $witch can now serve multiple departments without losing security or performance
Session #: 706
Layer 2 Switch with VLANs
• Logical evolution from switching table
• Port based VLAN identification – every port belongs to a VLAN
• Separate broadcast domains
VLAN 1 – OperationsVLAN 2 – Human ResourcesVLAN 3 – Marketing
Session #: 706
VLANs Across Switches
Session #: 706
VLAN Tags – Don't Lose my Bag
• DEN
• CHI
• NYC
• ELM
• SAT
Session #: 706
VLAN Tags – Ethernet Packets
• Ethernet packet fields• Header• Payload • End
• VLAN tagging information is added to the header, making it slightly longer
Session #: 706
VLAN Trunking Across Switches
The ports which join the switches are defined as belonging to native VLAN and a secondary VLAN. The
secondary VLAN sends ‘tagged’ packets so they can be segregated
Session #: 706
Read you loud and clear…
• VLAN compliant devices can accept tagged or untagged packets
• Packets without tags stay in the native VLAN (port based VLAN)
• Packets with tags go into the VLAN defined by the tag (if that VLAN is allowed on that port)
Session #: 706
Eh? What was that?
• Non VLAN compliant devices discard tagged packets –
they have an invalid header length!
Session #: 706
What Devices Read Tags?
• VLAN compliant switches
• VLAN compliant IP phones
• Microsoft Windows ? X
Session #: 706
Review - Who Sends Tags?
Devices are all in Port Based VLANs – no tagsTrunk between switches must send and receive tags
Session #: 706
802.1q VLAN Port Parameters
• Native VLAN (port based VLAN)
• Secondary VLANs
• Tagging
Session #: 706
IP Phone Deployment
• Avaya suggests that phones should always be in their own VLAN
• Increases security • Cuts down on broadcast traffic• Increases voice quality• Makes troubleshooting easier
Session #: 706
VLAN Deployment Options
2 VLANs, 2 Ports
2 VLANs, 1 Port!
Session #: 706
IP Phones have a Network Switch!
2 VLANs, 1 Port!
The phone contains aVLAN compliant
3 port network switch!!
Session #: 706
Detour – Phones & DHCP & VLANs
• DHCP is an ethernet broadcast request used by devices to get an IP number
• Broadcast packets do not cross VLANs
• Each VLAN needs its own DHCP Server
Session #: 706
Detour – Phones & DHCP & VLANs
• On bootup, the phone sends a DHCP request in the native VLAN (port VLAN)
• The phone is notified if there is a specific voice VLAN
• The phone sends a new DHCP request with the correct VLAN tag
Session #: 706
Review – Who Sends Tags?
The green VLAN is the native VLAN for both network switch ports
The blue VLAN is a secondary VLAN for both network switch ports
37Session #: 706
Broadway Suites, 100+ VLANs1942 Broadway
1877 Broadway
1800 Broadway 1301 Canyon
1300 Walnut
1919 14th
(Vectra Bank)
1801 13th
LEGENDSM Fiber (LX)MM Fiber (50 micron SX)
38Session #: 706
Do You Understand VLANs?
• You don't really understand something unless you can explain it to your grandmother...
Albert Einstein
39 Session #: 706
Final Reminders
• Please remember to turn in session evaluations
• The session number is: 706
40 Session #: 706
Thank YouThank You