Cisco Catalyst 3750-E Series User manual

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Catalyst 3750-E and 3560-E Switch
Software Configuration Guide
Cisco IOS Release 12.2(55)SE
August 2010
Text Part Number: OL-9775-08

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Catalyst 3750-E and 3560-E Switch Software Configuration Guide
© 2010 Cisco Systems, Inc. All rights reserved.

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CONTENTS
Preface xlix
Audience xlix
Purpose xlix
Conventions xlix
Related Publications l
Obtaining Documentation and Submitting a Service Request li
CHAPTER 1Overview 1-1
Features 1-1
Deployment Features 1-2
Performance Features 1-4
Management Options 1-5
Manageability Features 1-6
Availability and Redundancy Features 1-8
VLAN Features 1-9
Security Features 1-9
QoS and CoS Features 1-12
Layer 3 Features 1-14
Power over Ethernet Features 1-15
Monitoring Features 1-15
Default Settings After Initial Switch Configuration 1-16
Network Configuration Examples 1-19
Design Concepts for Using the Switch 1-19
Small to Medium-Sized Network Using Catalyst 3750-E and 3560-E Switches 1-26
Large Network Using Catalyst 3750-E and 3560-E Switches 1-28
Multidwelling Network Using Catalyst 3750-E Switches 1-31
Long-Distance, High-Bandwidth Transport Configuration 1-32
Where to Go Next 1-33
CHAPTER 2Using the Command-Line Interface 2-1
Understanding Command Modes 2-1
Understanding the Help System 2-3
Understanding Abbreviated Commands 2-3

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Understanding no and default Forms of Commands 2-4
Understanding CLI Error Messages 2-4
Using Configuration Logging 2-4
Using Command History 2-5
Changing the Command History Buffer Size 2-5
Recalling Commands 2-6
Disabling the Command History Feature 2-6
Using Editing Features 2-6
Enabling and Disabling Editing Features 2-6
Editing Commands through Keystrokes 2-7
Editing Command Lines that Wrap 2-8
Searching and Filtering Output of show and more Commands 2-9
Accessing the CLI 2-9
Accessing the CLI through a Console Connection or through Telnet 2-10
CHAPTER 3Assigning the Switch IP Address and Default Gateway 3-1
Understanding the Boot Process 3-1
Assigning Switch Information 3-2
Default Switch Information 3-3
Understanding DHCP-Based Autoconfiguration 3-3
DHCP Client Request Process 3-4
Understanding DHCP-based Autoconfiguration and Image Update 3-5
DHCP Autoconfiguration 3-5
DHCP Auto-Image Update 3-5
Limitations and Restrictions 3-6
Configuring DHCP-Based Autoconfiguration 3-6
DHCP Server Configuration Guidelines 3-7
Configuring the TFTP Server 3-7
Configuring the DNS 3-8
Configuring the Relay Device 3-8
Obtaining Configuration Files 3-9
Example Configuration 3-10
Configuring the DHCP Auto Configuration and Image Update Features 3-11
Configuring DHCP Autoconfiguration (Only Configuration File) 3-11
Configuring DHCP Auto-Image Update (Configuration File and Image) 3-12
Configuring the Client 3-14
Manually Assigning IP Information 3-15
Checking and Saving the Running Configuration 3-16
Configuring the NVRAM Buffer Size 3-17

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Modifying the Startup Configuration 3-18
Default Boot Configuration 3-18
Automatically Downloading a Configuration File 3-18
Specifying the Filename to Read and Write the System Configuration 3-19
Booting Manually 3-19
Booting a Specific Software Image 3-20
Controlling Environment Variables 3-21
Scheduling a Reload of the Software Image 3-24
Configuring a Scheduled Reload 3-24
Displaying Scheduled Reload Information 3-25
CHAPTER 4Configuring Cisco IOS Configuration Engine 4-1
Understanding Cisco Configuration Engine Software 4-1
Configuration Service 4-2
Event Service 4-3
NameSpace Mapper 4-3
What You Should Know About the CNS IDs and Device Hostnames 4-3
ConfigID 4-3
DeviceID 4-4
Hostname and DeviceID 4-4
Using Hostname, DeviceID, and ConfigID 4-4
Understanding Cisco IOS Agents 4-5
Initial Configuration 4-5
Incremental (Partial) Configuration 4-6
Synchronized Configuration 4-6
Configuring Cisco IOS Agents 4-6
Enabling Automated CNS Configuration 4-6
Enabling the CNS Event Agent 4-8
Enabling the Cisco IOS CNS Agent 4-9
Enabling an Initial Configuration 4-9
Enabling a Partial Configuration 4-13
Displaying CNS Configuration 4-14
CHAPTER 5Managing Switch Stacks 5-1
Understanding Switch Stacks 5-1
Switch Stack Membership 5-3
Stack Master Election and Re-Election 5-5
Switch Stack Bridge ID and Router MAC Address 5-7
Stack Member Numbers 5-7

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Stack Member Priority Values 5-8
Switch Stack Offline Configuration 5-8
Effects of Adding a Provisioned Switch to a Switch Stack 5-8
Effects of Replacing a Provisioned Switch in a Switch Stack 5-10
Effects of Removing a Provisioned Switch from a Switch Stack 5-10
Hardware Compatibility and SDM Mismatch Mode in Switch Stacks 5-10
Switch Stack Software Compatibility Recommendations 5-11
Stack Protocol Version Compatibility 5-11
Major Version Number Incompatibility Among Switches 5-11
Minor Version Number Incompatibility Among Switches 5-11
Understanding Auto-Upgrade and Auto-Advise 5-12
Auto-Upgrade and Auto-Advise Example Messages 5-13
Incompatible Software and Stack Member Image Upgrades 5-15
Switch Stack Configuration Files 5-15
Additional Considerations for System-Wide Configuration on Switch Stacks 5-16
Switch Stack Management Connectivity 5-16
Connectivity to the Switch Stack Through an IP Address 5-17
Connectivity to the Switch Stack Through an SSH Session 5-17
Connectivity to the Switch Stack Through Console Ports or Ethernet Management Ports 5-17
Connectivity to Specific Stack Members 5-18
Switch Stack Configuration Scenarios 5-18
Configuring the Switch Stack 5-20
Default Switch Stack Configuration 5-20
Enabling Persistent MAC Address 5-20
Assigning Stack Member Information 5-22
Assigning a Stack Member Number 5-22
Setting the Stack Member Priority Value 5-23
Provisioning a New Member for a Switch Stack 5-23
Accessing the CLI of a Specific Stack Member 5-25
Displaying Switch Stack Information 5-25
Troubleshooting Stacks 5-25
Manually Disabling a Stack Port 5-26
Re-Enabling a Stack Port While Another Member Starts 5-26
Understanding the show switch stack-ports summary Output 5-27
Identifying Loopback Problems 5-28
Software Loopback 5-28
Software Loopback Example: No Connected Stack Cable 5-29
Software Loopback Examples: Connected Stack Cables 5-29
Hardware Loopback 5-30

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Hardware Loopback Example: LINK OK event 5-30
Hardware Loop Example: LINK NOT OK Event 5-31
Finding a Disconnected Stack Cable 5-32
Fixing a Bad Connection Between Stack Ports 5-33
CHAPTER 6Clustering Switches 6-1
Understanding Switch Clusters 6-2
Cluster Command Switch Characteristics 6-3
Standby Cluster Command Switch Characteristics 6-3
Candidate Switch and Cluster Member Switch Characteristics 6-4
Planning a Switch Cluster 6-4
Automatic Discovery of Cluster Candidates and Members 6-5
Discovery Through CDP Hops 6-5
Discovery Through Non-CDP-Capable and Noncluster-Capable Devices 6-6
Discovery Through Different VLANs 6-7
Discovery Through Different Management VLANs 6-7
Discovery Through Routed Ports 6-8
Discovery of Newly Installed Switches 6-9
HSRP and Standby Cluster Command Switches 6-10
Virtual IP Addresses 6-11
Other Considerations for Cluster Standby Groups 6-11
Automatic Recovery of Cluster Configuration 6-12
IP Addresses 6-13
Hostnames 6-13
Passwords 6-14
SNMP Community Strings 6-14
Switch Clusters and Switch Stacks 6-14
TACACS+ and RADIUS 6-16
LRE Profiles 6-16
Using the CLI to Manage Switch Clusters 6-16
Catalyst 1900 and Catalyst 2820 CLI Considerations 6-17
Using SNMP to Manage Switch Clusters 6-17
CHAPTER 7Administering the Switch 7-1
Managing the System Time and Date 7-1
Understanding the System Clock 7-2
Understanding Network Time Protocol 7-2
Configuring NTP 7-4
Default NTP Configuration 7-4

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Configuring NTP Authentication 7-4
Configuring NTP Associations 7-5
Configuring NTP Broadcast Service 7-6
Configuring NTP Access Restrictions 7-8
Configuring the Source IP Address for NTP Packets 7-10
Displaying the NTP Configuration 7-11
Configuring Time and Date Manually 7-11
Setting the System Clock 7-11
Displaying the Time and Date Configuration 7-12
Configuring the Time Zone 7-12
Configuring Summer Time (Daylight Saving Time) 7-13
Configuring a System Name and Prompt 7-14
Default System Name and Prompt Configuration 7-15
Configuring a System Name 7-15
Understanding DNS 7-15
Default DNS Configuration 7-16
Setting Up DNS 7-16
Displaying the DNS Configuration 7-17
Creating a Banner 7-17
Default Banner Configuration 7-17
Configuring a Message-of-the-Day Login Banner 7-18
Configuring a Login Banner 7-19
Managing the MAC Address Table 7-19
Building the Address Table 7-20
MAC Addresses and VLANs 7-20
MAC Addresses and Switch Stacks 7-21
Default MAC Address Table Configuration 7-21
Changing the Address Aging Time 7-21
Removing Dynamic Address Entries 7-22
Configuring MAC Address Change Notification Traps 7-22
Configuring MAC Address Move Notification Traps 7-24
Configuring MAC Threshold Notification Traps 7-25
Adding and Removing Static Address Entries 7-27
Configuring Unicast MAC Address Filtering 7-28
Disabling MAC Address Learning on a VLAN 7-29
Displaying Address Table Entries 7-30
Managing the ARP Table 7-31

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CHAPTER 8Configuring SDM Templates 8-1
Understanding the SDM Templates 8-1
Dual IPv4 and IPv6 SDM Templates 8-2
SDM Templates and Switch Stacks 8-3
Configuring the Switch SDM Template 8-4
Default SDM Template 8-4
SDM Template Configuration Guidelines 8-4
Setting the SDM Template 8-5
Displaying the SDM Templates 8-6
CHAPTER 9Configuring Switch-Based Authentication 9-1
Preventing Unauthorized Access to Your Switch 9-1
Protecting Access to Privileged EXEC Commands 9-2
Default Password and Privilege Level Configuration 9-2
Setting or Changing a Static Enable Password 9-3
Protecting Enable and Enable Secret Passwords with Encryption 9-3
Disabling Password Recovery 9-5
Setting a Telnet Password for a Terminal Line 9-6
Configuring Username and Password Pairs 9-6
Configuring Multiple Privilege Levels 9-7
Setting the Privilege Level for a Command 9-8
Changing the Default Privilege Level for Lines 9-9
Logging into and Exiting a Privilege Level 9-9
Controlling Switch Access with TACACS+ 9-10
Understanding TACACS+ 9-10
TACACS+ Operation 9-12
Configuring TACACS+ 9-12
Default TACACS+ Configuration 9-13
Identifying the TACACS+ Server Host and Setting the Authentication Key 9-13
Configuring TACACS+ Login Authentication 9-14
Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services 9-16
Starting TACACS+ Accounting 9-17
Displaying the TACACS+ Configuration 9-17
Controlling Switch Access with RADIUS 9-17
Understanding RADIUS 9-18
RADIUS Operation 9-19
RADIUS Change of Authorization 9-19
Change-of-Authorization Requests 9-20
CoA Request Response Code 9-21

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CoA Request Commands 9-23
Stacking Guidelines for Session Termination 9-25
Configuring RADIUS 9-26
Default RADIUS Configuration 9-27
Identifying the RADIUS Server Host 9-27
Configuring RADIUS Login Authentication 9-29
Defining AAA Server Groups 9-31
Configuring RADIUS Authorization for User Privileged Access and Network Services 9-33
Starting RADIUS Accounting 9-34
Establishing a Session with a Router if the AAA Server is Unreachable 9-34
Configuring Settings for All RADIUS Servers 9-35
Configuring the Switch to Use Vendor-Specific RADIUS Attributes 9-35
Configuring the Switch for Vendor-Proprietary RADIUS Server Communication 9-37
Configuring CoA on the Switch 9-38
Monitoring and Troubleshooting CoA Functionality 9-39
Configuring RADIUS Server Load Balancing 9-39
Displaying the RADIUS Configuration 9-39
Controlling Switch Access with Kerberos 9-39
Understanding Kerberos 9-40
Kerberos Operation 9-42
Authenticating to a Boundary Switch 9-42
Obtaining a TGT from a KDC 9-42
Authenticating to Network Services 9-42
Configuring Kerberos 9-43
Configuring the Switch for Local Authentication and Authorization 9-43
Configuring the Switch for Secure Shell 9-45
Understanding SSH 9-45
SSH Servers, Integrated Clients, and Supported Versions 9-45
Limitations 9-46
Configuring SSH 9-46
Configuration Guidelines 9-46
Setting Up the Switch to Run SSH 9-46
Configuring the SSH Server 9-47
Displaying the SSH Configuration and Status 9-48
Configuring the Switch for Secure Socket Layer HTTP 9-49
Understanding Secure HTTP Servers and Clients 9-49
Certificate Authority Trustpoints 9-49
CipherSuites 9-51
Configuring Secure HTTP Servers and Clients 9-51