Configuring Layer 2 Protocol Tunneling; Understanding How Layer 2 Protocol Tunneling Works - Cisco WS-SUP32-GE-3B - Supervisor Engine 32 Software Configuration Manual

Configuring Layer 2 Protocol Tunneling

This chapter describes how to configure Layer 2 protocol tunneling on the Catalyst 6500 series switches.
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This chapter consists of these sections:
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Understanding How Layer 2 Protocol Tunneling Works

Layer 2 protocol tunneling allows Layer 2 protocol data units (PDUs) (CDP, STP, and VTP) to be
tunneled through a network. This section uses the following terminology:
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Without Layer 2 protocol tunneling, tunnel ports drop STP and VTP packets and process CDP packets. This
handling of the PDUs creates different spanning tree domains (different spanning tree roots) for the
customer switches. For example, STP for a VLAN on switch 1 (see
topology on switches 1, 2, and 3 without considering convergence parameters based on switches 4 and 5. To
provide a single spanning tree domain for the customer, a generic scheme to tunnel BPDUs was created
for control protocol PDUs (CDP, STP, and VTP). This process is referred to as Generic Bridge PDU
Tunneling (GBPT).
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 Layer 2 protocol tunneling.
Understanding How Layer 2 Protocol Tunneling Works, page 16-1
Configuring Support for Layer 2 Protocol Tunneling, page 16-2
Edge switch—The switch connected to the customer switch and placed on the boundary of the
service provider network (see
Layer 2 protocol tunnel port—A port on the edge switch on which a specific tunneled protocol can
be encapsulated or deencapsulated. The Layer 2 protocol tunnel port is configured through CLI
commands.
Tunneled PDU—A CDP, STP, or VTP PDU.
Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2ZY
C H A P T E R
Figure 16-1).
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Figure 16-1) builds a spanning tree
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