catalyst 2918 switch software configuration guide · contents vi catalyst 2918 switch software...

Catalyst 2918 Switch Software Configuration GuideCisco IOS Release 15.0(2)SE and LaterJanuary 2013

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Text Part Number: OL-27298-02

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Catalyst 2918 Switch Software Configuration Guide

©2009-2013 Cisco Systems, Inc. All rights reserved.

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C O N T E N T S

Preface xxvii

Audience xxvii

Purpose xxvii

Conventions xxvii

Related Publications xxviii

Obtaining Documentation, Obtaining Support, and Security Guidelines xxix

C H A P T E R 1 Overview 1-1

Features 1-1Ease-of-Deployment and Ease-of-Use Features 1-1Performance Features 1-2Management Options 1-3Manageability Features 1-4Availability and Redundancy Features 1-5VLAN Features 1-6Security Features 1-6QoS and CoS Features 1-7Monitoring Features 1-7

Default Settings After Initial Switch Configuration 1-8

Network Configuration Examples 1-10Design Concepts for Using the Switch 1-10Small to Medium-Sized Network Using Catalyst 2918 Switches 1-13

Where to Go Next 1-14

C H A P T E R 2 Using the Command-Line Interface 2-1

Understanding Command Modes 2-1

Understanding the Help System 2-3

Understanding Abbreviated Commands 2-3

Understanding no and default Forms of Commands 2-4

Understanding CLI Error Messages 2-4

Using Configuration Logging 2-5

Using Command History 2-5Changing the Command History Buffer Size 2-5

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Recalling Commands 2-6Disabling the Command History Feature 2-6

Using Editing Features 2-6Enabling and Disabling Editing Features 2-6Editing Commands through Keystrokes 2-7Editing Command Lines that Wrap 2-8

Searching and Filtering Output of show and more Commands 2-9

Accessing the CLI 2-9Accessing the CLI through a Console Connection or through Telnet 2-9

C H A P T E R 3 Assigning the Switch IP Address and Default Gateway 3-1

Understanding the Boot Process 3-1

Assigning Switch Information 3-2Default Switch Information 3-3Understanding DHCP-Based Autoconfiguration 3-3

DHCP Client Request Process 3-4Understanding DHCP-based Autoconfiguration and Image Update 3-5

DHCP Autoconfiguration 3-5DHCP Auto-Image Update 3-5Limitations and Restrictions 3-5

Configuring DHCP-Based Autoconfiguration 3-6DHCP Server Configuration Guidelines 3-6Configuring the TFTP Server 3-7Configuring the DNS 3-7Configuring the Relay Device 3-7Obtaining Configuration Files 3-8Example Configuration 3-9

Configuring the DHCP Auto Configuration and Image Update Features 3-11Configuring DHCP Autoconfiguration (Only Configuration File) 3-11Configuring DHCP Auto-Image Update (Configuration File and Image) 3-12Configuring the Client 3-13

Manually Assigning IP Information 3-14

Checking and Saving the Running Configuration 3-14

Modifying the Startup Configuration 3-15Default Boot Configuration 3-16Automatically Downloading a Configuration File 3-16Specifying the Filename to Read and Write the System Configuration 3-16Booting Manually 3-17Booting a Specific Software Image 3-18

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Controlling Environment Variables 3-18

Scheduling a Reload of the Software Image 3-20Configuring a Scheduled Reload 3-20Displaying Scheduled Reload Information 3-21

C H A P T E R 4 Configuring Cisco IOS CNS Agents 4-1

Understanding Cisco Configuration Engine Software 4-1Configuration Service 4-2Event Service 4-3

NameSpace Mapper 4-3What You Should Know About the CNS IDs and Device Hostnames 4-3

ConfigID 4-3DeviceID 4-4Hostname and DeviceID 4-4Using Hostname, DeviceID, and ConfigID 4-4

Understanding Cisco IOS Agents 4-5Initial Configuration 4-5Incremental (Partial) Configuration 4-6Synchronized Configuration 4-6

Configuring Cisco IOS Agents 4-6Enabling Automated CNS Configuration 4-6Enabling the CNS Event Agent 4-8Enabling the Cisco IOS CNS Agent 4-9

Enabling an Initial Configuration 4-9Enabling a Partial Configuration 4-11

Displaying CNS Configuration 4-12

C H A P T E R 5 Clustering Switches 5-1

Understanding Switch Clusters 5-1Cluster Command Switch Characteristics 5-2Standby Cluster Command Switch Characteristics 5-3Candidate Switch and Cluster Member Switch Characteristics 5-3

Planning a Switch Cluster 5-4Automatic Discovery of Cluster Candidates and Members 5-4

Discovery Through CDP Hops 5-4Discovery Through Non-CDP-Capable and Noncluster-Capable Devices 5-5Discovery Through Different VLANs 5-6Discovery Through Different Management VLANs 5-7Discovery of Newly Installed Switches 5-8

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HSRP and Standby Cluster Command Switches 5-9Virtual IP Addresses 5-10Other Considerations for Cluster Standby Groups 5-10Automatic Recovery of Cluster Configuration 5-11

IP Addresses 5-12Hostnames 5-12Passwords 5-12SNMP Community Strings 5-13TACACS+ and RADIUS 5-13LRE Profiles 5-13

Using the CLI to Manage Switch Clusters 5-13Catalyst 1900 and Catalyst 2820 CLI Considerations 5-14

Using SNMP to Manage Switch Clusters 5-14

C H A P T E R 6 Configuring SDM Templates 6-1

Understanding the SDM Templates 6-1

Configuring the Switch SDM Template 6-2

Displaying the SDM Templates 6-2

C H A P T E R 7 Administering the Switch 7-1

Managing the System Time and Date 7-1Understanding the System Clock 7-1Understanding Network Time Protocol 7-2NTP Version 4 7-3Configuring Time and Date Manually 7-4

Setting the System Clock 7-4Displaying the Time and Date Configuration 7-4Configuring the Time Zone 7-5Configuring Summer Time (Daylight Saving Time) 7-6

Configuring a System Name and Prompt 7-7Default System Name and Prompt Configuration 7-8Configuring a System Name 7-8Understanding DNS 7-8

Default DNS Configuration 7-9Setting Up DNS 7-9Displaying the DNS Configuration 7-10

Creating a Banner 7-10Default Banner Configuration 7-10Configuring a Message-of-the-Day Login Banner 7-11

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Configuring a Login Banner 7-12

Managing the MAC Address Table 7-12Building the Address Table 7-13MAC Addresses and VLANs 7-13Default MAC Address Table Configuration 7-13Changing the Address Aging Time 7-14Removing Dynamic Address Entries 7-14Configuring MAC Address Notification Traps 7-15Adding and Removing Static Address Entries 7-16Configuring Unicast MAC Address Filtering 7-17Displaying Address Table Entries 7-19

Managing the ARP Table 7-19

C H A P T E R 8 Configuring Switch-Based Authentication 8-1

Preventing Unauthorized Access to Your Switch 8-1

Protecting Access to Privileged EXEC Commands 8-2Default Password and Privilege Level Configuration 8-2Setting or Changing a Static Enable Password 8-3Protecting Enable and Enable Secret Passwords with Encryption 8-3Disabling Password Recovery 8-5Setting a Telnet Password for a Terminal Line 8-6Configuring Username and Password Pairs 8-6Configuring Multiple Privilege Levels 8-7

Setting the Privilege Level for a Command 8-8Changing the Default Privilege Level for Lines 8-9Logging into and Exiting a Privilege Level 8-9

Controlling Switch Access with TACACS+ 8-10Understanding TACACS+ 8-10TACACS+ Operation 8-12Configuring TACACS+ 8-12

Default TACACS+ Configuration 8-13Identifying the TACACS+ Server Host and Setting the Authentication Key 8-13Configuring TACACS+ Login Authentication 8-14Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services 8-16Starting TACACS+ Accounting 8-17

Displaying the TACACS+ Configuration 8-17

Controlling Switch Access with RADIUS 8-17Understanding RADIUS 8-18RADIUS Operation 8-19

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Configuring RADIUS 8-20Default RADIUS Configuration 8-20Identifying the RADIUS Server Host 8-20Configuring RADIUS Login Authentication 8-23Defining AAA Server Groups 8-25Configuring RADIUS Authorization for User Privileged Access and Network Services 8-27Starting RADIUS Accounting 8-28Configuring Settings for All RADIUS Servers 8-29Configuring the Switch to Use Vendor-Specific RADIUS Attributes 8-29Configuring the Switch for Vendor-Proprietary RADIUS Server Communication 8-31

Displaying the RADIUS Configuration 8-31

Configuring the Switch for Local Authentication and Authorization 8-32

Configuring the Switch for Secure Shell 8-33Understanding SSH 8-33

SSH Servers, Integrated Clients, and Supported Versions 8-33Limitations 8-34

Configuring SSH 8-34Configuration Guidelines 8-34Setting Up the Switch to Run SSH 8-35Configuring the SSH Server 8-36

Displaying the SSH Configuration and Status 8-36

Configuring the Switch for Secure Socket Layer HTTP 8-37Understanding Secure HTTP Servers and Clients 8-37

Certificate Authority Trustpoints 8-37CipherSuites 8-39

Configuring Secure HTTP Servers and Clients 8-39Default SSL Configuration 8-39SSL Configuration Guidelines 8-40Configuring a CA Trustpoint 8-40Configuring the Secure HTTP Server 8-41Configuring the Secure HTTP Client 8-42

Displaying Secure HTTP Server and Client Status 8-43

Configuring the Switch for Secure Copy Protocol 8-43Information About Secure Copy 8-44

C H A P T E R 9 Configuring IEEE 802.1x Port-Based Authentication 9-1

Understanding IEEE 802.1x Port-Based Authentication 9-1Device Roles 9-2Authentication Process 9-3

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Authentication Initiation and Message Exchange 9-5Ports in Authorized and Unauthorized States 9-6IEEE 802.1x Host Mode 9-7IEEE 802.1x Accounting 9-8IEEE 802.1x Accounting Attribute-Value Pairs 9-8Using IEEE 802.1x Authentication with VLAN Assignment 9-9Using IEEE 802.1x Authentication with Guest VLAN 9-10Using IEEE 802.1x Authentication with Restricted VLAN 9-11Using IEEE 802.1x Authentication with Voice VLAN Ports 9-12Using IEEE 802.1x Authentication with Port Security 9-13Using IEEE 802.1x Authentication with Wake-on-LAN 9-13Using IEEE 802.1x Authentication with MAC Authentication Bypass 9-13Common Session ID 9-14

Configuring IEEE 802.1x Authentication 9-15Default IEEE 802.1x Authentication Configuration 9-16IEEE 802.1x Authentication Configuration Guidelines 9-17

IEEE 802.1x Authentication 9-17VLAN Assignment and Guest VLAN 9-18MAC Authentication Bypass 9-18

Upgrading from a Previous Software Release 9-19Configuring IEEE 802.1x Authentication 9-19Configuring the Switch-to-RADIUS-Server Communication 9-21Configuring the Host Mode 9-22Configuring Periodic Re-Authentication 9-23Manually Re-Authenticating a Client Connected to a Port 9-24Changing the Quiet Period 9-24Changing the Switch-to-Client Retransmission Time 9-24Setting the Switch-to-Client Frame-Retransmission Number 9-25Setting the Re-Authentication Number 9-26Configuring IEEE 802.1x Accounting 9-27Configuring a Guest VLAN 9-28Configuring a Restricted VLAN 9-29Configuring 802.1x Authentication with Wake-on-LAN 9-30Configuring MAC Authentication Bypass 9-31Disabling IEEE 802.1x Authentication on the Port 9-31Resetting the IEEE 802.1x Authentication Configuration to the Default Values 9-32

Displaying IEEE 802.1x Statistics and Status 9-32

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C H A P T E R 10 Configuring Interface Characteristics 10-1

Understanding Interface Types 10-1Port-Based VLANs 10-1Switch Ports 10-2

Access Ports 10-2Trunk Ports 10-3

Connecting Interfaces 10-3

Using Interface Configuration Mode 10-4Procedures for Configuring Interfaces 10-5Configuring a Range of Interfaces 10-5Configuring and Using Interface Range Macros 10-7

Configuring Ethernet Interfaces 10-9Default Ethernet Interface Configuration 10-9Setting the Type of a Dual-Purpose Uplink Port 10-10Configuring Interface Speed and Duplex Mode 10-11

Speed and Duplex Configuration Guidelines 10-11Setting the Interface Speed and Duplex Parameters 10-12

Configuring IEEE 802.3x Flow Control 10-13Configuring Auto-MDIX on an Interface 10-14Adding a Description for an Interface 10-15

Configuring the System MTU 10-16

Monitoring and Maintaining the Interfaces 10-17Monitoring Interface Status 10-18Clearing and Resetting Interfaces and Counters 10-18Shutting Down and Restarting the Interface 10-19

C H A P T E R 11 Configuring VLANs 11-1

Understanding VLANs 11-1Supported VLANs 11-2VLAN Port Membership Modes 11-3

Configuring Normal-Range VLANs 11-4Token Ring VLANs 11-5Normal-Range VLAN Configuration Guidelines 11-5Saving VLAN Configuration 11-6Default Ethernet VLAN Configuration 11-6Creating or Modifying an Ethernet VLAN 11-7Deleting a VLAN 11-8Assigning Static-Access Ports to a VLAN 11-9

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Configuring Extended-Range VLANs 11-9Default VLAN Configuration 11-10Extended-Range VLAN Configuration Guidelines 11-10Creating an Extended-Range VLAN 11-11

Displaying VLANs 11-12

Configuring VLAN Trunks 11-12Trunking Overview 11-12

IEEE 802.1Q Configuration Considerations 11-13Default Layer 2 Ethernet Interface VLAN Configuration 11-14Configuring an Ethernet Interface as a Trunk Port 11-14

Interaction with Other Features 11-14Configuring a Trunk Port 11-15Defining the Allowed VLANs on a Trunk 11-16Changing the Pruning-Eligible List 11-17Configuring the Native VLAN for Untagged Traffic 11-17

Configuring Trunk Ports for Load Sharing 11-18Load Sharing Using STP Port Priorities 11-18Load Sharing Using STP Path Cost 11-20

Configuring VMPS 11-21Understanding VMPS 11-22

Dynamic-Access Port VLAN Membership 11-22Default VMPS Client Configuration 11-23VMPS Configuration Guidelines 11-23Configuring the VMPS Client 11-24

Entering the IP Address of the VMPS 11-24Configuring Dynamic-Access Ports on VMPS Clients 11-24Reconfirming VLAN Memberships 11-25Changing the Reconfirmation Interval 11-25Changing the Retry Count 11-26

Monitoring the VMPS 11-26Troubleshooting Dynamic-Access Port VLAN Membership 11-27VMPS Configuration Example 11-27

C H A P T E R 12 Configuring VTP 12-1

Understanding VTP 12-1The VTP Domain 12-2VTP Modes 12-3VTP Advertisements 12-3VTP Version 2 12-4

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VTP Pruning 12-4

Configuring VTP 12-6Default VTP Configuration 12-6VTP Configuration Guidelines 12-7

Domain Names 12-7Passwords 12-7VTP Version 12-8Configuration Requirements 12-8

Configuring a VTP Server 12-8Configuring a VTP Client 12-9Disabling VTP (VTP Transparent Mode) 12-10Enabling VTP Version 2 12-11Enabling VTP Pruning 12-12Adding a VTP Client Switch to a VTP Domain 12-12

Monitoring VTP 12-14

C H A P T E R 13 Configuring Voice VLAN 13-1

Understanding Voice VLAN 13-1Cisco IP Phone Voice Traffic 13-2Cisco IP Phone Data Traffic 13-2

Configuring Voice VLAN 13-3Default Voice VLAN Configuration 13-3Voice VLAN Configuration Guidelines 13-3Configuring a Port Connected to a Cisco 7960 IP Phone 13-4

Configuring Cisco IP Phone Voice Traffic 13-5

Displaying Voice VLAN 13-6

C H A P T E R 14 Configuring STP 14-1

Understanding Spanning-Tree Features 14-1STP Overview 14-2Spanning-Tree Topology and BPDUs 14-2Bridge ID, Switch Priority, and Extended System ID 14-3Spanning-Tree Interface States 14-4

Blocking State 14-5Listening State 14-6Learning State 14-6Forwarding State 14-6Disabled State 14-6

How a Switch or Port Becomes the Root Switch or Root Port 14-7

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Spanning Tree and Redundant Connectivity 14-7Spanning-Tree Address Management 14-8Accelerated Aging to Retain Connectivity 14-8Spanning-Tree Modes and Protocols 14-9Supported Spanning-Tree Instances 14-9Spanning-Tree Interoperability and Backward Compatibility 14-10STP and IEEE 802.1Q Trunks 14-10

Configuring Spanning-Tree Features 14-10Default Spanning-Tree Configuration 14-11Spanning-Tree Configuration Guidelines 14-12Changing the Spanning-Tree Mode. 14-13Disabling Spanning Tree 14-14Configuring the Root Switch 14-14Configuring a Secondary Root Switch 14-16Configuring Port Priority 14-16Configuring Path Cost 14-18Configuring the Switch Priority of a VLAN 14-19Configuring Spanning-Tree Timers 14-20

Configuring the Hello Time 14-20Configuring the Forwarding-Delay Time for a VLAN 14-21Configuring the Maximum-Aging Time for a VLAN 14-21Configuring the Transmit Hold-Count 14-22

Displaying the Spanning-Tree Status 14-22

C H A P T E R 15 Configuring MSTP 15-1

Understanding MSTP 15-2Multiple Spanning-Tree Regions 15-2IST, CIST, and CST 15-2

Operations Within an MST Region 15-3Operations Between MST Regions 15-3IEEE 802.1s Terminology 15-5

Hop Count 15-5Boundary Ports 15-6IEEE 802.1s Implementation 15-6

Port Role Naming Change 15-6Interoperation Between Legacy and Standard Switches 15-7Detecting Unidirectional Link Failure 15-7

Interoperability with IEEE 802.1D STP 15-8

Understanding RSTP 15-8

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Port Roles and the Active Topology 15-9Rapid Convergence 15-9Synchronization of Port Roles 15-11Bridge Protocol Data Unit Format and Processing 15-12

Processing Superior BPDU Information 15-12Processing Inferior BPDU Information 15-13

Topology Changes 15-13

Configuring MSTP Features 15-13Default MSTP Configuration 15-14MSTP Configuration Guidelines 15-14Specifying the MST Region Configuration and Enabling MSTP 15-15Configuring the Root Switch 15-17Configuring a Secondary Root Switch 15-18Configuring Port Priority 15-19Configuring Path Cost 15-20Configuring the Switch Priority 15-21Configuring the Hello Time 15-22Configuring the Forwarding-Delay Time 15-23Configuring the Maximum-Aging Time 15-23Configuring the Maximum-Hop Count 15-24Specifying the Link Type to Ensure Rapid Transitions 15-24Designating the Neighbor Type 15-25Restarting the Protocol Migration Process 15-25

Displaying the MST Configuration and Status 15-26

C H A P T E R 16 Configuring Optional Spanning-Tree Features 16-1

Understanding Optional Spanning-Tree Features 16-1Understanding Port Fast 16-2Understanding BPDU Guard 16-2Understanding BPDU Filtering 16-3Understanding UplinkFast 16-3Understanding BackboneFast 16-5Understanding EtherChannel Guard 16-7Understanding Root Guard 16-8Understanding Loop Guard 16-9

Configuring Optional Spanning-Tree Features 16-9Default Optional Spanning-Tree Configuration 16-9Optional Spanning-Tree Configuration Guidelines 16-10Enabling Port Fast 16-10

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Enabling BPDU Guard 16-11Enabling BPDU Filtering 16-12Enabling UplinkFast for Use with Redundant Links 16-13Enabling BackboneFast 16-13Enabling EtherChannel Guard 16-14Enabling Root Guard 16-15Enabling Loop Guard 16-15

Displaying the Spanning-Tree Status 16-16

C H A P T E R 17 Configuring DHCP Features and IP Source Guard Features 17-1

Understanding DHCP Snooping 17-1DHCP Server 17-2DHCP Relay Agent 17-2DHCP Snooping 17-2Option-82 Data Insertion 17-3DHCP Snooping Binding Database 17-6

Configuring DHCP Snooping 17-7Default DHCP Snooping Configuration 17-8DHCP Snooping Configuration Guidelines 17-8Configuring the DHCP Relay Agent 17-9Enabling DHCP Snooping and Option 82 17-10Enabling the DHCP Snooping Binding Database Agent 17-11

Displaying DHCP Snooping Information 17-12

Understanding DHCP Server Port-Based Address Allocation 17-13

Configuring DHCP Server Port-Based Address Allocation 17-14Default Port-Based Address Allocation Configuration 17-14Port-Based Address Allocation Configuration Guidelines 17-14Enabling DHCP Server Port-Based Address Allocation 17-15

Displaying DHCP Server Port-Based Address Allocation 17-17

C H A P T E R 18 Configuring IGMP Snooping 18-1

Understanding IGMP Snooping 18-1IGMP Versions 18-2Joining a Multicast Group 18-3Leaving a Multicast Group 18-4Immediate Leave 18-5IGMP Configurable-Leave Timer 18-5IGMP Report Suppression 18-5

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Configuring IGMP Snooping 18-6Default IGMP Snooping Configuration 18-6Enabling or Disabling IGMP Snooping 18-6Setting the Snooping Method 18-7Configuring a Multicast Router Port 18-8Configuring a Host Statically to Join a Group 18-9Enabling IGMP Immediate Leave 18-9Configuring the IGMP Leave Timer 18-10Configuring TCN-Related Commands 18-11

Controlling the Multicast Flooding Time After a TCN Event 18-11Recovering from Flood Mode 18-12Disabling Multicast Flooding During a TCN Event 18-12

Configuring the IGMP Snooping Querier 18-13Disabling IGMP Report Suppression 18-14

Displaying IGMP Snooping Information 18-15

Configuring IGMP Filtering and Throttling 18-16Default IGMP Filtering and Throttling Configuration 18-17Configuring IGMP Profiles 18-17Applying IGMP Profiles 18-18Setting the Maximum Number of IGMP Groups 18-19Configuring the IGMP Throttling Action 18-19

Displaying IGMP Filtering and Throttling Configuration 18-21

C H A P T E R 19 Configuring IPv6 MLD Snooping 19-1

Understanding MLD Snooping 19-1MLD Messages 19-2MLD Queries 19-2Multicast Client Aging Robustness 19-3Multicast Router Discovery 19-3MLD Reports 19-3MLD Done Messages and Immediate-Leave 19-4Topology Change Notification Processing 19-4

Configuring IPv6 MLD Snooping 19-4Default MLD Snooping Configuration 19-5MLD Snooping Configuration Guidelines 19-5Enabling or Disabling MLD Snooping 19-6Configuring a Static Multicast Group 19-7Configuring a Multicast Router Port 19-7Enabling MLD Immediate Leave 19-8

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Configuring MLD Snooping Queries 19-9Disabling MLD Listener Message Suppression 19-10

Displaying MLD Snooping Information 19-11

C H A P T E R 20 Configuring Port-Based Traffic Control 20-1

Configuring Storm Control 20-1Understanding Storm Control 20-1Default Storm Control Configuration 20-3Configuring Storm Control and Threshold Levels 20-3Configuring Small-Frame Arrival Rate 20-5

Configuring Protected Ports 20-6Default Protected Port Configuration 20-6Protected Port Configuration Guidelines 20-6Configuring a Protected Port 20-7

Configuring Port Blocking 20-7Default Port Blocking Configuration 20-7Blocking Flooded Traffic on an Interface 20-7

Configuring Port Security 20-8Understanding Port Security 20-8

Secure MAC Addresses 20-9Security Violations 20-9

Default Port Security Configuration 20-11Port Security Configuration Guidelines 20-11Enabling and Configuring Port Security 20-12Enabling and Configuring Port Security Aging 20-16

Configuring Protocol Storm Protection 20-17Understanding Protocol Storm Protection 20-17Default Protocol Storm Protection Configuration 20-18Enabling Protocol Storm Protection 20-18

Displaying Port-Based Traffic Control Settings 20-19

C H A P T E R 21 Configuring CDP 21-1

Understanding CDP 21-1

Configuring CDP 21-2Default CDP Configuration 21-2Configuring the CDP Characteristics 21-2Disabling and Enabling CDP 21-3Disabling and Enabling CDP on an Interface 21-4

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Monitoring and Maintaining CDP 21-5

C H A P T E R 22 Configuring LLDP and LLDP-MED 22-1

Understanding LLDP and LLDP-MED 22-1LLDP 22-1LLDP-MED 22-2

Configuring LLDP and LLDP-MED 22-3Default LLDP Configuration 22-3Configuration Guidelines 22-3Enabling LLDP 22-4Configuring LLDP Characteristics 22-4Configuring LLDP-MED TLVs 22-5Configuring Network-Policy TLV 22-6

Monitoring and Maintaining LLDP and LLDP-MED 22-8

C H A P T E R 23 Configuring UDLD 23-1

Understanding UDLD 23-1Modes of Operation 23-1Methods to Detect Unidirectional Links 23-2

Configuring UDLD 23-3Default UDLD Configuration 23-4Configuration Guidelines 23-4Enabling UDLD Globally 23-4Enabling UDLD on an Interface 23-5Resetting an Interface Disabled by UDLD 23-5

Displaying UDLD Status 23-6

C H A P T E R 24 Configuring SPAN 24-1

Understanding SPAN 24-1Local SPAN 24-2SPAN Concepts and Terminology 24-2

SPAN Sessions 24-2Monitored Traffic 24-3Source Ports 24-4Source VLANs 24-4VLAN Filtering 24-5Destination Port 24-5

SPAN Interaction with Other Features 24-6

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Configuring SPAN 24-7Default SPAN Configuration 24-7Configuring Local SPAN 24-7

SPAN Configuration Guidelines 24-7Creating a Local SPAN Session 24-8Creating a Local SPAN Session and Configuring Incoming Traffic 24-10Specifying VLANs to Filter 24-12

Displaying SPAN Status 24-13

C H A P T E R 25 Configuring RMON 25-1

Understanding RMON 25-1

Configuring RMON 25-2Default RMON Configuration 25-3Configuring RMON Alarms and Events 25-3Collecting Group History Statistics on an Interface 25-5Collecting Group Ethernet Statistics on an Interface 25-5

Displaying RMON Status 25-6

C H A P T E R 26 Configuring System Message Logging 26-1

Understanding System Message Logging 26-1

Configuring System Message Logging 26-2System Log Message Format 26-2Default System Message Logging Configuration 26-3Disabling Message Logging 26-3Setting the Message Display Destination Device 26-4Synchronizing Log Messages 26-5Enabling and Disabling Time Stamps on Log Messages 26-7Enabling and Disabling Sequence Numbers in Log Messages 26-7Defining the Message Severity Level 26-8Limiting Syslog Messages Sent to the History Table and to SNMP 26-9Enabling the Configuration-Change Logger 26-10Configuring UNIX Syslog Servers 26-11

Logging Messages to a UNIX Syslog Daemon 26-11Configuring the UNIX System Logging Facility 26-12

Displaying the Logging Configuration 26-13

C H A P T E R 27 Configuring SNMP 27-1

Understanding SNMP 27-1

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SNMP Versions 27-2SNMP Manager Functions 27-3SNMP Agent Functions 27-4SNMP Community Strings 27-4Using SNMP to Access MIB Variables 27-4SNMP Notifications 27-5SNMP ifIndex MIB Object Values 27-5

Configuring SNMP 27-6Default SNMP Configuration 27-6SNMP Configuration Guidelines 27-7Disabling the SNMP Agent 27-7Configuring Community Strings 27-8Configuring SNMP Groups and Users 27-9Configuring SNMP Notifications 27-11Setting the Agent Contact and Location Information 27-15Limiting TFTP Servers Used Through SNMP 27-15SNMP Examples 27-16

Displaying SNMP Status 27-17

C H A P T E R 28 Configuring Network Security with ACLs 28-1

Understanding ACLs 28-1ACL Overview 28-2Handling Fragmented and Unfragmented Traffic 28-3

Configuring IPv4 ACLs 28-4Creating Standard and Extended IPv4 ACLs 28-4

Access List Numbers 28-5Creating a Numbered Standard ACL 28-6Creating a Numbered Extended ACL 28-7Resequencing ACEs in an ACL 28-11Creating Named Standard and Extended ACLs 28-11Using Time Ranges with ACLs 28-13Including Comments in ACLs 28-14

Applying an IPv4 ACL to a Terminal Line 28-15Applying an IPv4 ACL to a VLAN Interface 28-15Hardware and Software Treatment of IP ACLs 28-16Troubleshooting ACLs 28-17IPv4 ACL Configuration Examples 28-17

Numbered ACLs 28-18Extended ACLs 28-18

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Named ACLs 28-18Time Range Applied to an IP ACL 28-19Commented IP ACL Entries 28-19

Displaying IPv4 ACL Configuration 28-20

C H A P T E R 29 Configuring QoS 29-1

Understanding QoS 29-1Basic QoS Model 29-3Classification 29-3Queueing Overview 29-4

Weighted Tail Drop 29-4Queueing on Ingress Queues 29-4Queueing on Egress Queues 29-5

Packet Modification 29-6

Configuring Standard QoS 29-6Default Standard QoS Configuration 29-7

Default Ingress Queue Configuration 29-7Default Egress Queue Configuration 29-7

General QoS Guidelines 29-8Enabling QoS Globally 29-8Configuring Classification Using Port Trust States 29-9

Configuring the Trust State on Ports within the QoS Domain 29-9Configuring the CoS Value for an Interface 29-10Enabling DSCP Transparency Mode 29-11

Configuring Ingress Queue Characteristics 29-12Mapping CoS Values to an Ingress Queue 29-12Configuring the Ingress Priority Queue 29-13

Configuring Egress Queue Characteristics 29-14Configuration Guidelines 29-14Mapping CoS Values to an Egress Queue and to a Threshold ID 29-14Configuring the Egress Expedite Queue 29-15

Displaying Standard QoS Information 29-16

C H A P T E R 30 Configuring EtherChannels 30-1

Understanding EtherChannels 30-1EtherChannel Overview 30-2Port-Channel Interfaces 30-3Port Aggregation Protocol 30-4

PAgP Modes 30-4

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PAgP Interaction with Other Features 30-5Link Aggregation Control Protocol 30-5

LACP Modes 30-5LACP Interaction with Other Features 30-6

EtherChannel On Mode 30-6Load Balancing and Forwarding Methods 30-6

Configuring EtherChannels 30-8Default EtherChannel Configuration 30-9EtherChannel Configuration Guidelines 30-9Configuring Layer 2 EtherChannels 30-10Configuring EtherChannel Load Balancing 30-12Configuring the PAgP Learn Method and Priority 30-13Configuring LACP Hot-Standby Ports 30-14

Configuring the LACP System Priority 30-15Configuring the LACP Port Priority 30-15

Displaying EtherChannel, PAgP, and LACP Status 30-16

C H A P T E R 31 Troubleshooting 31-1

Recovering from a Software Failure 31-2

Recovering from a Lost or Forgotten Password 31-3Procedure with Password Recovery Enabled 31-4Procedure with Password Recovery Disabled 31-6

Recovering from a Command Switch Failure 31-7Replacing a Failed Command Switch with a Cluster Member 31-8Replacing a Failed Command Switch with Another Switch 31-9

Recovering from Lost Cluster Member Connectivity 31-11

Preventing Autonegotiation Mismatches 31-11

SFP Module Security and Identification 31-11

Monitoring SFP Module Status 31-12

Using Ping 31-12Understanding Ping 31-12Executing Ping 31-13

Using Layer 2 Traceroute 31-13Understanding Layer 2 Traceroute 31-14Usage Guidelines 31-14Displaying the Physical Path 31-15

Using IP Traceroute 31-15Understanding IP Traceroute 31-15

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Executing IP Traceroute 31-16

Using TDR 31-17Understanding TDR 31-17Running TDR and Displaying the Results 31-17

Using Debug Commands 31-17Enabling Debugging on a Specific Feature 31-18Enabling All-System Diagnostics 31-18Redirecting Debug and Error Message Output 31-19

Using the show platform forward Command 31-19

Using the crashinfo Files 31-21Basic crashinfo Files 31-21Extended crashinfo Files 31-21

Memory Consistency Check Routines 31-22Displaying TCAM Memory Consistency Check Errors 31-22

Troubleshooting Tables 31-23Troubleshooting CPU Utilization 31-23

Possible Symptoms of High CPU Utilization 31-23Verifying the Problem and Cause 31-23

A P P E N D I X A Working with the Cisco IOS File System, Configuration Files, and Software Images A-1

Working with the Flash File System A-1Displaying Available File Systems A-2Setting the Default File System A-3Displaying Information about Files on a File System A-3Changing Directories and Displaying the Working Directory A-3Creating and Removing Directories A-4Copying Files A-4Deleting Files A-5Creating, Displaying, and Extracting tar Files A-5

Creating a tar File A-6Displaying the Contents of a tar File A-6Extracting a tar File A-7

Displaying the Contents of a File A-7

Working with Configuration Files A-8Guidelines for Creating and Using Configuration Files A-8Configuration File Types and Location A-9Creating a Configuration File By Using a Text Editor A-9Copying Configuration Files By Using TFTP A-10

Preparing to Download or Upload a Configuration File By Using TFTP A-10

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Downloading the Configuration File By Using TFTP A-11Uploading the Configuration File By Using TFTP A-11

Copying Configuration Files By Using FTP A-12Preparing to Download or Upload a Configuration File By Using FTP A-12Downloading a Configuration File By Using FTP A-13Uploading a Configuration File By Using FTP A-14

Copying Configuration Files By Using RCP A-15Preparing to Download or Upload a Configuration File By Using RCP A-16Downloading a Configuration File By Using RCP A-16Uploading a Configuration File By Using RCP A-17

Clearing Configuration Information A-18Clearing the Startup Configuration File A-18Deleting a Stored Configuration File A-18

Working with Software Images A-19Image Location on the Switch A-19tar File Format of Images on a Server or Cisco.com A-20Copying Image Files By Using TFTP A-21

Preparing to Download or Upload an Image File By Using TFTP A-21Downloading an Image File By Using TFTP A-22Uploading an Image File By Using TFTP A-23

Copying Image Files By Using FTP A-24Preparing to Download or Upload an Image File By Using FTP A-24Downloading an Image File By Using FTP A-25Uploading an Image File By Using FTP A-27

Copying Image Files By Using RCP A-28Preparing to Download or Upload an Image File By Using RCP A-28Downloading an Image File By Using RCP A-29Uploading an Image File By Using RCP A-31

A P P E N D I X B Unsupported Commands in Cisco IOS Release 15.0(2)SE B-1

Access Control Lists B-1Unsupported Privileged EXEC Commands B-1Unsupported Global Configuration Commands B-1Unsupported Route-Map Configuration Commands B-1

Boot Loader Commands B-2Unsupported Global Configuration Commands B-2

Debug Commands B-2Unsupported Privileged EXEC Commands B-2

Embedded Syslog Manager B-2

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Unsupported Global Configuration Commands B-2Unsupported Privileged EXEC Commands B-2

IEEE 802.1x Commands B-2Unsupported Privileged EXEC Command B-2Unsupported Global Configuration Command B-2

IGMP Snooping Commands B-3Unsupported Global Configuration Commands B-3

Interface Commands B-3Unsupported Privileged EXEC Commands B-3Unsupported Global Configuration Commands B-3Unsupported Interface Configuration Commands B-3

MAC Address Commands B-3Unsupported Privileged EXEC Commands B-3Unsupported Global Configuration Commands B-4

Miscellaneous B-4Unsupported Privileged EXEC Commands B-4Unsupported Global Configuration Commands B-4

Network Address Translation (NAT) Commands B-4Unsupported Privileged EXEC Commands B-4

QoS B-4Unsupported Global Configuration Command B-4Unsupported Interface Configuration Commands B-5Unsupported Policy-Map Configuration Command B-5

RADIUS B-5Unsupported Global Configuration Commands B-5

SNMP B-5Unsupported Global Configuration Commands B-5

Spanning Tree B-5Unsupported Global Configuration Command B-5Unsupported Interface Configuration Command B-6

VLAN B-6Unsupported Global Configuration Command B-6Unsupported vlan-config Command B-6Unsupported User EXEC Commands B-6

VTP B-6Unsupported Privileged EXEC Commands B-6

I N D E X

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Preface

AudienceThis guide is for the networking professional managing the Catalyst 2918 switch, hereafter referred to as the switch. Before using this guide, you should have experience working with the Cisco IOS software and be familiar with the concepts and terminology of Ethernet and local area networking.

PurposeThis guide provides the information that you need to configure Cisco IOS software features on your switch. The Catalyst 2918 software provides enterprise-class intelligent services.

This guide provides procedures for using the commands that have been created or changed for use with the Catalyst 2918 switch. It does not provide detailed information about these commands. For detailed information about these commands, see the Catalyst 2918 Switch Command Reference for this release. For information about the standard Cisco IOS Release 15.0 commands, see the Cisco IOS documentation set available from Cisco.com.

This guide does not provide detailed information on the graphical user interfaces (GUIs) for the embedded device manager that you can use to manage the switch. However, the concepts in this guide are applicable to the GUI user. For information about the device manager, see the switch online help. This guide does not describe system messages you might encounter or how to install your switch. For more information, see the Catalyst 2918 Switch System Message Guide for this release and the Catalyst 2918 Switch Hardware Installation Guide.

For documentation updates, see the release notes for this release.

ConventionsThis publication uses these conventions to convey instructions and information:

Command descriptions use these conventions:

• Commands and keywords are in boldface text.

• Arguments for which you supply values are in italic.

• Square brackets ([ ]) mean optional elements.

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• Braces ({ }) group required choices, and vertical bars ( | ) separate the alternative elements.

• Braces and vertical bars within square brackets ([{ | }]) mean a required choice within an optional element.

Interactive examples use these conventions:

• Terminal sessions and system displays are in screen font.

• Information you enter is in boldface screen font.

• Nonprinting characters, such as passwords or tabs, are in angle brackets (< >).

Notes, cautions, and timesavers use these conventions and symbols:

Note Means reader take note. Notes contain helpful suggestions or references to materials not contained in this manual.

Caution Means reader be careful. In this situation, you might do something that could result in equipment damage or loss of data.

Related PublicationsThese documents provide complete information about the switch and are available from this Cisco.com site:

http://www.cisco.com/web/CN/products/products_netsol/switches/products/ca2928/index.html

• Release Notes for the Catalyst 2918 Switch

Note Before installing, configuring, or upgrading the switch, refer to the release notes on Cisco.com for the latest information.

• Catalyst 2918 Switch Software Configuration Guide

• Catalyst 2918 Switch Command Reference

• Catalyst 2918 Switch System Message Guide

• Auto Smartports Configuration Guide

• Catalyst 2918 Switch Getting Started Guide

• Catalyst 2918 Switch Hardware Installation Guide

• Regulatory Compliance and Safety Information for the Catalyst 2918 Switch

• Cisco Small Form-Factor Pluggable Modules Installation Notes

xxviiiCatalyst 2918 Switch Software Configuration Guide

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http://www.cisco.com/web/CN/products/products_netsol/switches/products/ca2928/index.htmlhttp://www.cisco.com/web/CN/products/products_netsol/switches/products/ca2928/index.html

Preface

Obtaining Documentation, Obtaining Support, and Security Guidelines

For information on obtaining documentation, submitting a service request, and gathering additional information, see the monthly What’s New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at:

http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html

Subscribe to the What’s New in Cisco Product Documentation as a Really Simple Syndication (RSS) feed and set content to be delivered directly to your desktop using a reader application. The RSS feeds are a free service and Cisco currently supports RSS version 2.0.

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Preface

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C H A P T E R 1

Overview

This chapter provides these topics about the Catalyst 2918 switch software:

• Features, page 1-1

• Default Settings After Initial Switch Configuration, page 1-8

• Network Configuration Examples, page 1-10

• Where to Go Next, page 1-14

In this document, unless otherwise indicated, IP refers to IP Version 4 (IPv4).

FeaturesSome features described in this chapter are available only on the cryptographic (supports encryption) version of the software. You must obtain authorization to use this feature and to download the cryptographic version of the software from Cisco.com. For more information, see the release notes for this release.

• Ease-of-Deployment and Ease-of-Use Features, page 1-1

• Performance Features, page 1-2

• Management Options, page 1-3

• Manageability Features, page 1-4 (includes a feature requiring the cryptographic version of the software)

• Availability and Redundancy Features, page 1-5

• VLAN Features, page 1-6

• Security Features, page 1-6 (includes a feature requiring the cryptographic version of the software)

• QoS and CoS Features, page 1-7

• Monitoring Features, page 1-7

Ease-of-Deployment and Ease-of-Use Features• Express Setup for quickly configuring a switch for the first time with basic IP information, contact

information, switch and Telnet passwords, and Simple Network Management Protocol (SNMP) information through a browser-based program. For more information about Express Setup, see the getting started guide.

1-1Catalyst 2918 Switch Software Configuration Guide

Chapter 1 OverviewFeatures

• User-defined and Cisco-default Smartports macros for creating custom switch configurations for simplified deployment across the network.

• Auto Smartports

– Cisco-default and user-defined macros for dynamic port configuration based on the device type detected on the port.

– Enhancements to add support for global macros, last-resort macros, event trigger control, access points, EtherChannels, auto-QoS with Cisco Medianet, and IP phones.

– Auto Smartports enhancement to enable auto-QoS on a CDP-capable Cisco digital media player.

• An embedded device manager GUI for configuring and monitoring a single switch through a web browser. For information about launching the device manager, see the getting started guide. For more information about the device manager, see the switch online help.

• Switch clustering technology for

– Unified configuration, monitoring, authentication, and software upgrade of multiple, cluster-capable switches, regardless of their geographic proximity and interconnection media, including Ethernet, Fast Ethernet, Fast EtherChannel, small form-factor pluggable (SFP) modules, Gigabit Ethernet, and Gigabit EtherChannel connections. For a list of cluster-capable switches, see the release notes.

– Automatic discovery of candidate switches and creation of clusters of up to 16 switches that can be managed through a single IP address.

– Extended discovery of cluster candidates that are not directly connected to the command switch.

• Smart Install to allow a single point of management (director) in a network. You can use Smart Install to provide zero touch image and configuration upgrade of newly deployed switches and image and configuration downloads for any client switches. For more information, see the Cisco Smart Install Configuration Guide.

• Smart Install enhancements in Cisco IOS Release 12.2(55)SE supporting client backup files, zero-touch replacement for clients with the same product-ID, automatic generation of the image list file, configurable file repository, hostname changes, transparent connection of the director to client, and USB storage for image and seed configuration.

Performance Features• Autosensing of port speed and autonegotiation of duplex mode on all switch ports for optimizing

bandwidth

• Automatic-medium-dependent interface crossover (auto-MDIX) capability on 10/100 and 10/100/1000 Mb/s interfaces and on 10/100/1000 BASE-TX SFP module interfaces that enables the interface to automatically detect the required cable connection type (straight-through or crossover) and to configure the connection appropriately

• Support for up to 9000 bytes for frames that are bridged in hardware, and up to 2000 bytes for frames that are bridged by software

• IEEE 802.3x flow control on all ports (the switch does not send pause frames)

• EtherChannel for enhanced fault tolerance and for providing up to 8 Gb/s (Gigabit EtherChannel) or 800 Mb/s (Fast EtherChannel) full-duplex bandwidth among switches, routers, and servers

• Port Aggregation Protocol (PAgP) and Link Aggregation Control Protocol (LACP) for automatic creation of EtherChannel links


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• Forwarding of Layer 2 packets at Gigabit line rate

• Per-port storm control for preventing broadcast, multicast, and unicast storms

• Port blocking on forwarding unknown Layer 2 unknown unicast, multicast, and bridged broadcast traffic

• Protocol storm protection to control the rate of incoming protocol traffic to a switch by dropping packets that exceed a specified ingress rate

• Internet Group Management Protocol (IGMP) snooping for IGMP Versions 1, 2, and 3 for efficiently forwarding multimedia and multicast traffic

• IGMP report suppression for sending only one IGMP report per multicast router query to the multicast devices (supported only for IGMPv1 or IGMPv2 queries)

• IGMP snooping querier support to configure switch to generate periodic IGMP general query messages

• IGMP filtering for controlling the set of multicast groups to which hosts on a switch port can belong

• IGMP throttling for configuring the action when the maximum number of entries is in the IGMP forwarding table

• IGMP leave timer for configuring the leave latency for the network

• Support for Multicast Listener Discovery (MLD) snooping on LAN Lite images with the dual-ipv4-ipv6 template. This enables efficient distribution of IPv6 multicast data to clients and routers in a switched network

• Switch Database Management (SDM) templates for allocating system resources to maximize support for user-selected features

• Configurable small-frame arrival threshold to prevent storm control when small frames (64 bytes or less) arrive on an interface at a specified rate (the threshold)

• Memory consistency check routines to detect and correct invalid ternary content addressable memory (TCAM) table entries.

Management Options• An embedded device manager—The device manager is a GUI that is integrated in the software

image. You use it to configure and to monitor a single switch. For information about launching the device manager, see the getting started guide. For more information about the device manager, see the switch online help.

• CLI—The Cisco IOS software supports desktop- and multilayer-switching features. You can access the CLI either by connecting your management station directly to the switch console port or by using Telnet from a remote management station. For more information about the CLI, see Chapter 2, “Using the Command-Line Interface.”

• SNMP—SNMP management applications such as CiscoWorks2000 LAN Management Suite (LMS) and HP OpenView. You can manage from an SNMP-compatible management station that is running platforms such as HP OpenView or SunNet Manager. The switch supports a comprehensive set of MIB extensions and four remote monitoring (RMON) groups. For more information about using SNMP, see Chapter 27, “Configuring SNMP.”


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• Cisco IOS Configuration Engine (previously known to as the Cisco IOS CNS agent)-—Configuration service automates the deployment and management of network devices and services. You can automate initial configurations and configuration updates by generating switch-specific configuration changes, sending them to the switch, executing the configuration change, and logging the results.

For more information about CNS, see Chapter 4, “Configuring Cisco IOS CNS Agents.”

Manageability Features• CNS embedded agents for automating switch management, configuration storage, and delivery

• DHCP for automating configuration of switch information (such as IP address, default gateway, hostname, and Domain Name System [DNS] and TFTP server names)

• DHCP relay for forwarding User Datagram Protocol (UDP) broadcasts, including IP address requests, from DHCP clients

• DHCP server for automatic assignment of IP addresses and other DHCP options to IP hosts

• DHCP-based autoconfiguration and image update to download a specified configuration a new image to a large number of switches

• Directed unicast requests to a DNS server for identifying a switch through its IP address and its corresponding hostname and to a TFTP server for administering software upgrades from a TFTP server

• Address Resolution Protocol (ARP) for identifying a switch through its IP address and its corresponding MAC address

• Unicast MAC address filtering to drop packets with specific source or destination MAC addresses

• Cisco Discovery Protocol (CDP) Versions 1 and 2 for network topology discovery and mapping between the switch and other Cisco devices on the network

• Link Layer Discovery Protocol (LLDP) for interoperability with third-party IP phones

• Support for the LLDP-MED location TLV that provides location information from the switch to the endpoint device

• CDP and LLDP enhancements for exchanging location information with video end points for dynamic location-based content distribution from servers

• Network Time Protocol (NTP) version 4 for NTP time synchronization for both IPv4 and IPv6

• Network Time Protocol version 4 (NTPv4) to support both IPv4 and IPv6 and compatibility with NTPv3

• Cisco IOS File System (IFS) for providing a single interface to all file systems that the switch uses

• Configuration logging to log and to view changes to the switch configuration

• Unique device identifier to provide product identification information through a show inventory user EXEC command display

• In-band management access through the device manager over a Netscape Navigator or Microsoft Internet Explorer browser session

• In-band management access for up to 16 simultaneous Telnet connections for multiple CLI-based sessions over the network


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• In-band management access for up to five simultaneous, encrypted Secure Shell (SSH) connections for multiple CLI-based sessions over the network (requires the cryptographic version of the software)

• Support for SSH over both IPv4 and IPv6

• In-band management access through SNMP Versions 1, 2c, and 3 get and set requests

• Out-of-band management access through the switch console port to a directly attached terminal or to a remote terminal through a serial connection or a modem

• Secure Copy Protocol (SCP) feature to provide a secure and authenticated method for copying switch configuration or switch image files (requires the cryptographic version of the software)

• DHCP Snooping enhancement to support the selection of a fixed string-based format for the circuit-id sub-option of the Option 82 DHCP field

Availability and Redundancy Features• UniDirectional Link Detection (UDLD) and aggressive UDLD for detecting and disabling

unidirectional links on fiber-optic interfaces caused by incorrect fiber-optic wiring or port faults

• IEEE 802.1D Spanning Tree Protocol (STP) for redundant backbone connections and loop-free networks. STP has these features:

– Up to 64 spanning-tree instances supported

– Per-VLAN spanning-tree plus (PVST+) for load balancing across VLANs

– Rapid PVST+ for load balancing across VLANs and providing rapid convergence of spanning-tree instances

– UplinkFast and BackboneFast for fast convergence after a spanning-tree topology change and for achieving load balancing between redundant uplinks, including Gigabit uplinks

• IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) for grouping VLANs into a spanning-tree instance and for providing multiple forwarding paths for data traffic and load balancing and rapid per-VLAN Spanning-Tree plus (rapid-PVST+) based on the IEEE 802.1w Rapid Spanning Tree Protocol (RSTP) for rapid convergence of the spanning tree by immediately changing root and designated ports to the forwarding state

• Optional spanning-tree features available in PVST+, rapid-PVST+, and MSTP mode:

– Port Fast for eliminating the forwarding delay by enabling a port to immediately change from the blocking state to the forwarding state

– BPDU guard for shutting down Port Fast-enabled ports that receive bridge protocol data units (BPDUs)

– BPDU filtering for preventing a Port Fast-enabled port from sending or receiving BPDUs

– Root guard for preventing switches outside the network core from becoming the spanning-tree root

– Loop guard for preventing alternate or root ports from becoming designated ports because of a failure that leads to a unidirectional link


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VLAN Features• Support for up to 64 VLANs for assigning users to VLANs associated with appropriate network

resources, traffic patterns, and bandwidth

• Support for VLAN IDs in the 1 to 4094 range as allowed by the IEEE 802.1Q standard

• VLAN Query Protocol (VQP) for dynamic VLAN membership

• IEEE 802.1Q trunking encapsulation on all ports for network moves, adds, and changes; management and control of broadcast and multicast traffic; and network security by establishing VLAN groups for high-security users and network resources

• Dynamic Trunking Protocol (DTP) for negotiating trunking on a link between two devices and for negotiating the type of trunking encapsulation (IEEE 802.1Q) to be used

• VLAN Trunking Protocol (VTP) and VTP pruning for reducing network traffic by restricting flooded traffic to links destined for stations receiving the traffic

• Voice VLAN for creating subnets for voice traffic from Cisco IP Phones

• VLAN 1 minimization for reducing the risk of spanning-tree loops or storms by allowing VLAN 1 to be disabled on any individual VLAN trunk link. With this feature enabled, no user traffic is sent or received on the trunk. The switch CPU continues to send and receive control protocol frames.

• Port security on a PVLAN host to limit the number of MAC addresses learned on a port, or define which MAC addresses may be learned on a port

Security Features• Password-protected access (read-only and read-write access) to management interfaces (device

manager, Network Assistant, and the CLI) for protection against unauthorized configuration changes

• Multilevel security for a choice of security level, notification, and resulting actions

• Static MAC addressing for ensuring security

• Protected port option for restricting the forwarding of traffic to designated ports on the same switch

• Port security option for limiting and identifying MAC addresses of the stations allowed to access the port

• VLAN aware port security option to shut down the VLAN on the port when a violation occurs, instead of shutting down the entire port

• Port security aging to set the aging time for secure addresses on a port

• BPDU guard for shutting down a Port Fast-configured port when an invalid configuration occurs

• IEEE 802.1x port-based authentication to prevent unauthorized devices (clients) from gaining access to the network. These features are supported:

– VLAN assignment for restricting IEEE 802.1x-authenticated users to a specified VLAN

– Port security for controlling access to IEEE 802.1x ports

– Voice VLAN to permit a Cisco IP Phone to access the voice VLAN regardless of the authorized or unauthorized state of the port

– IP phone detection enhancement to detect and recognize a Cisco IP phone.

– Guest VLAN to provide limited services to non-IEEE 802.1x-compliant users


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– IEEE 802.1x accounting to track network usage

– Support for 802.1x Wake-on-LAN on the LAN Lite image

• TACACS+, a proprietary feature for managing network security through a TACACS server for both IPv4 and IPv6

• RADIUS for verifying the identity of, granting access to, and tracking the actions of remote users through authentication, authorization, and accounting (AAA) services for both IPv4 and IPv6

• Secure Socket Layer (SSL) Version 3.0 support for the HTTP 1.1 server authentication, encryption, and message integrity and HTTP client authentication to allow secure HTTP communications (requires the cryptographic version of the software)

• Voice aware IEEE 802.1x security

QoS and CoS Features• Classification

– IEEE 802.1p CoS marking priorities on a per-port basis for protecting the performance of mission-critical applications

– Trusted port states (CoS and IP precedence) within a QoS domain and with a port bordering another QoS domain

• Ingress queueing and scheduling

– Two configurable ingress queues for user traffic (one queue can be the priority queue)

– Weighted tail drop (WTD) as the congestion-avoidance mechanism for managing the queue lengths and providing drop precedences for different traffic classifications

– Thresholds and queue-lengths are predefined and fixed

– Shaped round robin (SRR) as the scheduling service for specifying the rate at which packets are sent to the internal ring

– Ratios and buffers/thresholds are predefined and fixed

• Egress queues and scheduling

– Four egress queues per port

– WTD as the congestion-avoidance mechanism for managing the queue lengths and providing drop precedences for different traffic classifications

– Thresholds and queue-lengths are predefined and fixed

– SRR as the scheduling service for specifying the rate at which packets are dequeued to the egress interface

– Ratios and buffers/thresholds are predefined and fixed

Monitoring Features• Switch LEDs that provide port- and switch-level status

• MAC address notification traps and RADIUS accounting for tracking users on a network by storing the MAC addresses that the switch has learned or removed

• Switched Port Analyzer (SPAN) for traffic monitoring on any port or VLAN


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Chapter 1 OverviewDefault Settings After Initial Switch Configuration

• SPAN support of Intrusion Detection Systems (IDS) to monitor, repel, and report network security violations

• Four groups (history, statistics, alarms, and events) of embedded RMON agents for network monitoring and traffic analysis

• Syslog facility for logging system messages about authentication or authorization errors, resource issues, and time-out events

• Layer 2 traceroute to identify the physical path that a packet takes from a source device to a destination device

• Time Domain Reflector (TDR) to diagnose and resolve cabling problems on 10/100 and 10/100/1000 copper Ethernet ports

• SFP module diagnostic management interface to monitor physical or operational status of an SFP module

Default Settings After Initial Switch ConfigurationThe switch is designed for plug-and-play operation, requiring only that you assign basic IP information to the switch and connect it to the other devices in your network. If you have specific network needs, you can change the interface-specific and system-wide settings.

Note For information about assigning an IP address by using the browser-based Express Setup program, see the getting started guide. For information about assigning an IP address by using the CLI-based setup program, see the hardware installation guide.

If you do not configure the switch at all, the switch operates with these default settings:

• Default switch IP address, subnet mask, and default gateway is 0.0.0.0. For more information, see Chapter 3, “Assigning the Switch IP Address and Default Gateway.”

• Default domain name is not configured. For more information, see Chapter 3, “Assigning the Switch IP Address and Default Gateway.”

• Switch cluster is disabled. For more information about switch clusters, see Chapter 5, “Clustering Switches.”

• No passwords are defined. For more information, see Chapter 7, “Administering the Switch.”

• System name and prompt is Switch. For more information, see Chapter 7, “Administering the Switch.”

• NTP is enabled. For more information, see Chapter 7, “Administering the Switch.”

• DNS is enabled. For more information, see Chapter 7, “Administering the Switch.”

• TACACS+ is disabled. For more information, see Chapter 8, “Configuring Switch-Based Authentication.”

• RADIUS is disabled. For more information, see Chapter 8, “Configuring Switch-Based Authentication.”

• The standard HTTP server and Secure Socket Layer (SSL) HTTPS server are both enabled. For more information, see Chapter 8, “Configuring Switch-Based Authentication.”

• IEEE 802.1x is disabled. For more information, see Chapter 9, “Configuring IEEE 802.1x Port-Based Authentication.”


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Chapter 1 OverviewDefault Settings After Initial Switch Configuration

• Port parameters

– Interface speed and duplex mode is autonegotiate. For more information, see Chapter 10, “Configuring Interface Characteristics.”

– Auto-MDIX is enabled. For more information, see Chapter 10, “Configuring Interface Characteristics.”

– Flow control is off. For more information, see

• No Smartports macros are defined. For more information, see the Auto Smartports Configuration Guide.

• VLANs

– Default VLAN is VLAN 1. For more information, see Chapter 11, “Configuring VLANs.”

– VLAN trunking setting is dynamic auto (DTP). For more information, see Chapter 11, “Configuring VLANs.”

– Trunk encapsulation is negotiate. For more information, see Chapter 11, “Configuring VLANs.”

– VTP mode is server. For more information, see Chapter 12, “Configuring VTP.”

– VTP version is Version 1. For more information, see Chapter 12, “Configuring VTP.”

– Voice VLAN is disabled. For more information, see Chapter 13, “Configuring Voice VLAN.”

• STP, PVST+ is enabled on VLAN 1. For more information, see Chapter 14, “Configuring STP.”

• MSTP is disabled. For more information, see Chapter 15, “Configuring MSTP.”

• Optional spanning-tree features are disabled. For more information, see Chapter 16, “Configuring Optional Spanning-Tree Features.”

• IGMP snooping is enabled. No IGMP filters are applied. For more information, see Chapter 18, “Configuring IGMP Snooping.”

• IGMP throttling setting is deny. For more information, see Chapter 18, “Configuring IGMP Snooping.”

• The IGMP snooping querier feature is disabled. For more information, see Chapter 18, “Configuring IGMP Snooping.”

• Port-based traffic

– Broadcast, multicast, and unicast storm control is disabled. For more information, see Chapter 20, “Configuring Port-Based Traffic Control.”

– No protected ports are defined. For more information, see Chapter 20, “Configuring Port-Based Traffic Control.”

– Unicast and multicast traffic flooding is not blocked. For more information, see Chapter 20, “Configuring Port-Based Traffic Control.”

– No secure ports are configured. For more information, see Chapter 20, “Configuring Port-Based Traffic Control.”

• CDP is enabled. For more information, see Chapter 21, “Configuring CDP.”

• UDLD is disabled. For more information, see Chapter 23, “Configuring UDLD.”

• SPAN disabled. For more information, see Chapter 24, “Configuring SPAN.”

• RMON is disabled. For more information, see Chapter 25, “Configuring RMON.”

• Syslog messages are enabled and appear on the console. For more information, see Chapter 26, “Configuring System Message Logging.”


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Chapter 1 OverviewNetwork Configuration Examples

• SNMP is enabled (Version 1). For more information, see Chapter 27, “Configuring SNMP.”

• QoS is disabled. For more information, see Chapter 29, “Configuring QoS.”

• No EtherChannels are configured. For more information, see Chapter 30, “Configuring EtherChannels.”

Network Configuration ExamplesThis section provides network configuration concepts and includes examples of using the switch to create dedicated network segments and interconnecting the segments through Fast Ethernet and Gigabit Ethernet connections.

• “Design Concepts for Using the Switch” section on page 1-10

• “Small to Medium-Sized Network Using Catalyst 2918 Switches” section on page 1-13

Design Concepts for Using the SwitchIAs your network users compete for network bandwidth, it takes longer to send and receive data. When you configure your network, consider the bandwidth required by your network users and the relative priority of the network applications that they use.

Table 1-1 describes what can cause network performance to degrade and how you can configure your network to increase the bandwidth available to your network users.

Table 1-1 Increasing Network Performance

Network Demands Suggested Design Methods

Too many users on a single network segment and a growing number of users accessing the Internet

• Create smaller network segments so that fewer users share the bandwidth, and use VLANs and IP subnets to place the network resources in the same logical network as the users who access those resources most.

• Use full-duplex operation between the switch and its connected workstations.

• Increased power of new PCs, workstations, and servers

• High bandwidth demand from networked applications (such as e-mail with large attached files) and from bandwidth-intensive applications (such as multimedia)

• Connect global resources—such as servers and routers to which the network users require equal access—directly to the high-speed switch ports so that they have their own high-speed segment.

• Use the EtherChannel feature between the switch and its connected servers and routers.


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Bandwidth alone is not the only consideration when designing your network. As your network traffic profiles evolve, consider providing network services that can support applications for voice and data integration, multimedia integration, application prioritization, and security. Table 1-2 describes some network demands and how you can meet them.

You can use the switches to create the following:

• Cost-effective Gigabit-to-the-desktop for high-performance workgroups (Figure 1-1)—For high-speed access to network resources, you can use the Cisco Catalyst 2918 switches in the access layer to provide Gigabit Ethernet to the desktop. To prevent congestion, use QoS DSCP marking priorities on these switches. For high-speed IP forwarding at the distribution layer, connect the switches in the access layer to a Gigabit multilayer switch with routing capability, such as a Catalyst 3750 switch, or to a router.

The first illustration is of an isolated high-performance workgroup, where the Catalyst 2918 switches are connected to Catalyst 3750 switches in the distribution layer. The second illustration is of a high-performance workgroup in a branch office, where the Catalyst 2918 switches are connected to a router in the distribution layer.

Each switch in this configuration provides users with a dedicated 1-Gb/s connection to network resources. Using SFP modules also provides flexibility in media and distance options through fiber-optic connections.

Table 1-2 Providing Network Services

Network Demands Suggested Design Methods

Efficient bandwidth usage for multimedia applications and guaranteed bandwidth for critical applications

• Use IGMP snooping to efficiently forward multimedia and multicast traffic.

• Use other QoS mechanisms such as packet classification, marking, scheduling, and congestion avoidance to classify traffic with the appropriate priority level, thereby providing maximum flexibility and support for mission-critical, unicast, and multicast and multimedia applications.

High demand on network redundancy and availability to provide always on mission-critical applications

• Use VLAN trunks and BackboneFast for traffic-load balancing on the uplink ports so that the uplink port with a lower relative port cost is selected to carry the VLAN traffic.

An evolving demand for IP telephony • Use QoS to prioritize applications such as IP telephony during congestion and to help control both delay and jitter within the network.

• Use switches that support at least two queues per port to prioritize voice and data traffic as either high- or low-priority, based on IEEE 802.1p/Q. The switch supports at least four queues per port.

• Use voice VLAN IDs (VVIDs) to provide separate VLANs for voice traffic.


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Figure 1-1 High-Performance Workgroup (Gigabit-to-the-Desktop)

• Server aggregation (Figure 1-2)—You can use the switches to interconnect groups of servers, centralizing physical security and administration of your network. For high-speed IP forwarding at the distribution layer, connect the switches in the access layer to multilayer switches with routing capability. The Gigabit interconnections minimize latency in the data flow.

QoS and policing on the switches provide preferential treatment for certain data streams. They segment traffic streams into different paths for processing. Security features on the switch ensure rapid handling of packets.

Fault tolerance from the server racks to the core is achieved through dual homing of servers connected to switches, which have redundant Gigabit EtherChannels.

Using dual SFP module uplinks from the switches provides redundant uplinks to the network core. Using SFP modules provides flexibility in media and distance options through fiber-optic connections.

Figure 1-2 Server Aggregation

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Access-layerCatalystswitches

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Small to Medium-Sized Network Using Catalyst 2918 SwitchesFigure 1-3 shows a configuration for a network of up to 500 employees. This network uses Catalyst 2918 switches with high-speed connections to two routers. This ensures connectivity to the Internet, WAN, and mission-critical network resources in case one of the routers fails. The switches are using EtherChannel for load sharing.

The switches are connected to workstations and local servers. The server farm includes a call-processing server running Cisco CallManager software. Cisco CallManager controls call processing, routing, and Cisco IP Phone features and configuration. The switches are interconnected through Gigabit interfaces.

This network uses VLANs to logically segment the network into well-defined broadcast groups and for security management. Data and multimedia traffic are configured on the same VLAN. Voice traffic from the Cisco IP Phones are configured on separate VVIDs. If data, multimedia, and voice traffic are assigned to the same VLAN, only one VLAN can be configured per wiring closet.

When an end station in one VLAN needs to communicate with an end station in another VLAN, a router routes the traffic to the destination VLAN. In this network, the routers are providing inter-VLAN routing. VLAN access control lists (VLAN maps) on the switch provide intra-VLAN security and prevent unauthorized users from accessing critical areas of the network.

In addition to inter-VLAN routing, the routers provide QoS mechanisms such as DSCP priorities to prioritize the different types of network traffic and to deliver high-priority traffic. If congestion occurs, QoS drops low-priority traffic to allow delivery of high-priority traffic.

Cisco CallManager controls call processing, routing, and Cisco IP Phone features and configuration. Users with workstations running Cisco SoftPhone software can place, receive, and control calls from their PCs. Using Cisco IP Phones, Cisco CallManager software, and Cisco SoftPhone software integrates telephony and IP networks, and the IP network supports both voice and data.

The routers also provide firewall services, Network Address Translation (NAT) services, voice-over-IP (VoIP) gateway services, and WAN and Internet access.

Figure 1-3 Catalyst 2918 Switches in a Collapsed Backbone Configuration

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Chapter 1 OverviewWhere to Go Next

Where to Go NextBefore configuring the switch, review these sections for startup information:

• Chapter 2, “Using the Command-Line Interface”

• Chapter 3, “Assigning the Switch IP Address and Default Gateway”

To locate and download MIBs for a specific Cisco product and release, use the Cisco MIB Locator:http://cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.


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http://cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml

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C H A P T E R 2

Using the Command-Line Interface

This chapter describes the Cisco IOS command-line interface (CLI) and how to use it to configure your Catalyst 2918 switch. It contains these sections:

• Understanding Command Modes, page 2-1

• Understanding the Help System, page 2-3

• Understanding Abbreviated Commands, page 2-3

• Understanding no and default Forms of Commands, page 2-4

• Understanding CLI Error Messages, page 2-4

• Using Configuration Logging, page 2-5

• Using Command History, page 2-5

• Using Editing Features, page 2-6

• Searching and Filtering Output of show and more Commands, page 2-9

• Accessing the CLI, page 2-9

Understanding Command ModesThe Cisco IOS user interface is divided into many different modes. The commands available to you depend on which mode you are currently in. Enter a question mark (?) at the system prompt to obtain a list of commands available for each command mode.

When you start a session on the switch, you begin in user mode, often called user EXEC mode. Only a limited subset of the commands are available in user EXEC mode. For example, most of the user EXEC commands are one-time commands, such as show commands, which show the current configuration status, and clear commands, which clear counters or interfaces. The user EXEC commands are not saved when the switch reboots.

To have access to all commands, you must enter privileged EXEC mode. Normally, you must enter a password to enter privileged EXEC mode. From this mode, you can enter any privileged EXEC command or enter global configuration mode.

Using the configuration modes (global, interface, and line), you can make changes to the running configuration. If you save the configuration, these commands are stored and used when the switch reboots. To access the various configuration modes, you must start at global configuration mode. From global configuration mode, you can enter interface configuration mode and line configuration mode.


Chapter 2 Using the Command-Line InterfaceUnderstanding Command Modes

Table 2-1 describes the main command modes, how to access each one, the prompt you see in that mode, and how to exit the mode. The examples in the table use the hostname Switch.

Table 2-1 Command Mode Summary

Mode Access Method Prompt Exit Method About This Mode

User EXEC Begin a session with your switch.

Switch> Enter logout or quit.

Use this mode to

• Change terminal settings.

• Perform basic tests.

• Display system information.

Privileged EXEC While in user EXEC mode, enter the enable command.

Switch# Enter disable to exit.

Use this mode to verify commands that you have entered. Use a password to protect access to this mode.

Global configuration While in privileged EXEC mode, enter the configure command.

Switch(config)# To exit to privileged EXEC mode, enter exit or end, or press Ctrl-Z.

Use this mode to configure parameters that apply to the entire switch.

VLAN configuration While in global configuration mode, enter the vlan vlan-id command.

Switch(config-vlan)# To exit to global configuration mode, enter the exit command.

To return to privileged EXEC mode, press Ctrl-Z or enter end.

Use this mode to configure VLAN parameters. When VTP mode is transparent, you can create extended-range VLANs (VLAN IDs greater than 1005) and save configurations in the switch startup configuration file.

Interface configuration

While in global configuration mode, enter the interface command (with a specific interface).

Switch(config-if)# To exit to global configuration mode, enter exit.


Use this mode to configure parameters for the Ethernet ports.

For information about defining interfaces, see the “Using Interface Configuration Mode” section on page 10-4.

To configure multiple interfaces with the same parameters, see the “Configuring a Range of Interfaces” section on page 10-5.

Line configuration While in global configuration mode, specify a line with the line vty or line console command.

Switch(config-line)# To exit to global configuration mode, enter exit.


Use this mode to configure parameters for the terminal line.


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Chapter 2 Using the Command-Line InterfaceUnderstanding the Help System

For more detailed information on the command modes, see the command reference guide for this release.

Understanding the Help SystemYou can enter a question mark (?) at the system prompt to display a list of commands available for each command mode. You can also obtain a list of associated keywords and arguments for any command, as shown in Table 2-2.

Understanding Abbreviated CommandsYou need to enter only enough characters for the switch to recognize the command as unique.

This example shows how to enter the show configuration privileged EXEC command in an abbreviated form:

Switch# show conf

Table 2-2 Help Summary

Command Purpose

help Obtain a brief description of the help system in any command mode.

abbreviated-command-entry? Obtain a list of commands that begin with a particular character string.

For example:

Switch# di?dir disable disconnect

abbreviated-command-entry Complete a partial command name.

For example:

Switch# sh confSwitch# show configuration

? List all commands available for a particular command mode.

For example:

Switch> ?

command ? List the associated keywords for a command.

For example:

Switch> show ?

command keyword ? List the associated arguments for a keyword.

For example:

Switch(config)# cdp holdtime ? Length of time (in sec) that receiver must keep this packet


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Chapter 2 Using the Command-Line InterfaceUnderstanding no and default Forms of Commands

Understanding no and default Forms of CommandsAlmost every configuration command also has a no form. In general, use the no form to disable a feature or function or reverse the action of a command. For example, the no shutdown interface configuration command reverses the shutdown of an interface. Use the command without the keyword no to re-enable a disabled feature or to enable a feature that is disabled by default.

Configuration commands can also have a default form. The default form of a command returns the command setting to its default. Most commands are disabled by default, so the default form is the same as the no form. However, some commands are enabled by default and have variables set to certain default values. In these cases, the default command enables the command and sets variables to their default values.

Understanding CLI Error MessagesTable 2-3 lists some error messages that you might encounter while using the CLI to configure your switch.

Table 2-3 Common CLI Error Messages

Error Message Meaning How to Get Help

% Ambiguous command: "show con"

You did not enter enough characters for your switch to recognize the command.

Re-enter the command followed by a question mark (?) with a space between the command and the question mark.

The possible keywords that you can enter with the command appear.

% Incomplete command. You did not enter all the keywords or values required by this command.

Re-enter the command followed by a question mark (?) with a space between the command and the question mark.


% Invalid input detected at ‘^’ marker.

You entered the command incorrectly. The caret (^) marks the point of the error.

Enter a question mark (?) to display all the commands that are available in this command mode.



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Chapter 2 Using the Command-Line InterfaceUsing Configuration Logging

Using Configuration LoggingYou can log and view changes to the switch configuration. You can use the Configuration Change Logging and Notification feature to track changes on a per-session and per-user basis. The logger tracks each configuration command that is applied, the user who entered the command, the time that the command was entered, and the parser return code for the command. This feature includes a mechanism for asynchronous notification to registered applications whenever the configuration changes. You can choose to have the notifications sent to the syslog.

For more information, see the Configuration Change Notification and Logging feature module at this URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/product

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