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Contents
vi
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide
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Release 8.2GLX
78-15908-01
EtherChannel Configuration Examples
6-12
Configuration Example of a Four-Port Fast EtherChannel
6-12
Configuration Example of a Two-Port Gigabit EtherChannel
6-14
Understanding LACP
6-16
LACP Modes
6-16
LACP Parameters
6-17
Configuring EtherChannel Using LACP
6-18
Specifying the EtherChannel Protocol
6-18
Specifying the System Priority
6-19
Specifying the Port Priority
6-19
Specifying an Administrative Key Value
6-19
Changing the Channel Mode
6-20
Specifying the Channel Path Cost
6-21
Specifying the Channel VLAN Cost
6-21
Clearing LACP Statistics
6-21
Displaying EtherChannel Traffic Utilization
6-21
Disabling an EtherChannel
6-22
Displaying Spanning Tree-Related Information for EtherChannels
6-22
C H A P T E R
7
Configuring Spanning Tree
7-1
Understanding How STPs Work
7-2
Understanding How a Topology Is Created
7-2
Understanding How a Switch or Port Becomes the Root Switch or Root Port
7-3
Understanding BPDUs
7-4
Calculating and Assigning Port Costs
7-4
Understanding Spanning Tree Port States
7-5
Understanding How PVST+ and MISTP Modes Work
7-11
PVST+ Mode
7-12
Rapid PVST+
7-12
MISTP Mode
7-12
MISTP-PVST+ Mode
7-13
Understanding How Bridge Identifiers Work
7-13
MAC Address Allocation
7-13
MAC Address Reduction
7-13
Understanding How MST Works
7-14
Rapid Spanning Tree Protocol
7-16
MST-to-SST Interoperability
7-17
Common Spanning Tree
7-18
MST Instances
7-18