Configuring Ieee 802.1Q Tunneling; Understanding How 802.1Q Tunneling Works - Cisco WS-SUP32-GE-3B - Supervisor Engine 32 Software Configuration Manual

Configuring IEEE 802.1Q Tunneling

This chapter describes how to configure IEEE 802.1Q tunneling on the Catalyst 6500 series switches.
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This chapter consists of these sections:
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Understanding How 802.1Q Tunneling Works

802.1Q tunneling enables service providers to use a single VLAN to support customers who have
multiple VLANs, while preserving customer VLAN IDs and keeping traffic in different customer
VLANs segregated.
A port configured to support 802.1Q tunneling is called a tunnel port. When you configure tunneling,
you assign a tunnel port to a VLAN that you dedicate to tunneling, which then becomes a tunnel VLAN.
To keep customer traffic segregated, each customer requires a separate tunnel VLAN, but that one tunnel
VLAN supports all of the customer's VLANs.
802.1Q tunneling is not restricted to point-to-point tunnel configurations. Any tunnel port in a tunnel
VLAN is a tunnel entry and exit point. An 802.1Q tunnel can have as many tunnel ports as are needed
to connect customer switches.
The customer switches are trunk connected, but with 802.1Q tunneling, the service provider switches
only use one service provider VLAN to carry all the customer VLANs, instead of directly carrying all
the customer VLANs.
With 802.1Q tunneling, tagged customer traffic comes from an 802.1Q trunk port on a customer device
and enters the service-provider edge switch through a tunnel port. The link between the 802.1Q trunk
port on a customer device and the tunnel port is called an asymmetrical link because one end is
OL-11439-03
For complete syntax and usage information for the commands used in this chapter, refer to the
Catalyst Supervisor Engine 32 PISA Cisco IOS Command Reference, Release 12.2ZY, at this URL:
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2ZY/command/reference/cmdr
ef.html
The WS-X6548-GE-TX, WS-X6548V-GE-TX, WS-X6148-GE-TX, and WS-X6148V-GE-TX
switching modules do not support IEEE 802.1Q tunneling.
Understanding How 802.1Q Tunneling Works, page 15-1
802.1Q Tunneling Configuration Guidelines and Restrictions, page 15-3
Configuring 802.1Q Tunneling, page 15-6
Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2ZY
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