Switch File Management 93 Filename Conventions IOS image files are named according to a predefined format. The filenames follow this basic template: mmmmm-fffff-mm.vvvv.bin ■ mmmmm represents the Catalyst switch model (for example, c3550 corresponds to Catalyst 3550, cat4000 to Catalyst 4000, and c6sup22 to Catalyst 6500 Supervisor II). ■ fffff represents the feature sets included in the image; generally, i followed by anything denotes an IP feature set, s is the IP “Plus,” k denotes a cryptographic feature set (Data Encryption Standard [DES] or 3DES), j is the enterprise set, p is for service providers, and d is the desktop (IP, IPX, AppleTalk, DECnet) feature set. ■ mm denotes the file format: The first letter is m if the image runs in RAM, and the second letter is z if the image is Zip compressed. ■ vvvv represents the IOS version, in the format vvv-mmm.bbb; the major release (vvv) is given first and followed by a dash; then, the maintenance release (mmm) is given and followed by a period. The build level (bbb) is given using one or more letters and a number. The first letter denotes the type of build: E means an early deployment of features. The next letter is the interim build level, where A means the first build, and so on. The number following denotes the number of times the interim build has been incrementally released. Therefore, 121-12c.EA1 means version 12.1(12c)EA1, or early deployment build A1 (the first “A” build) of the 12.1(12c) code. ■ .bin flags the image file as a binary executable (not readable text). Configuration Files The switch configuration is a file containing all the commands needed to configure each switch feature and function. Here are three of the most common configuration files: ■ startup-config—When a switch first boots up, the startup-config file is read, parsed, and executed. The startup-config is stored in NVRAM (actually the nvram: file system) so it survives power failures. ■ running-config—While a switch is running, this contains a copy of the current state of every command in use. This file is dynamic, such that it is updated with each configuration command entered. The running-config’s contents are volatile, causing all commands in it to be lost during a power failure or a switch reload. (To preserve the running-config, it must be copied into the startup- config prior to the next switch reload.) 1-58720-077-5.book Page 93 Tuesday, August 19, 2003 3:16 PM 94 Chapter 4: Switch Configuration ■ vlan.dat—As VLANs are defined or changed, their configurations are entered into the VLAN database file, vlan.dat. This file is updated as you make configuration changes to the VLAN database on a switch and as any VLAN Trunking Protocol (VTP) updates occur. The VLAN database (vlan.dat) is stored in Flash memory and is normally configured through the vlan database or vlan configuration commands. Its contents are preserved across a power failure or reload. Other Catalyst Switch Files You can also find several other files stored in the file systems on a Catalyst switch. Most of the time, you will not need to do anything with them. They are mentioned here for your understanding and if you need to access the information they contain. These files can include the following: ■ system_env_vars—A text file containing system variables such as the MAC address, model number, serial number, and various module information. This file is consulted to get the system information displayed by the show version command. ■ crashinfo—A file or directory containing text output from previous switch crashes. This is normally stored and accessed as flash:crashinfo (a file) or crashinfo: (a directory). Moving Catalyst Switch Files Around A switch can copy files to and from various locations, including those in Table 4-2. Table 4-2 Locations of Catalyst Switch Files File System Name Function flash: Flash memory, usually containing bootable IOS image files (some models emulate nvram: here) bootflash: Flash memory, usually containing bootable IOS image files slot0: Optional removable Flash card memory; can store any type of files nvram: NVRAM area, usually containing the startup-config file system: RAM area; contains the running-config file, as well as a directory of all dynamic switch memory areas tftp: An external TFTP server where any type of switch file can be stored or retrieved; no user authentication needed ftp: An external FTP server where any type of switch file can be stored or retrieved; user authentication required rcp: An external rcp server where any type of switch file can be stored or retrieved; user authentication required 1-58720-077-5.book Page 94 Tuesday, August 19, 2003 3:16 PM Switch File Management 95 Cisco IOS Software allows you to navigate and manipulate the Flash file system in much the same way other operating systems, such as UNIX and DOS, do. In Flash memory, you can find plain text files, binary executable files, and directories. You are free to “move” up and down into directories. You can also copy, rename, or delete files. In the EXEC mode, you are always positioned in the “root” directory, flash:, by default. To perform a function in the Flash file system, use one of the following commands: ■ dir [flash:[directory]]—Show a list of all files in the current Flash directory or the directory given. ■ cd flash:directory—Change directory to the directory given. ■ cd —Change directory one level up. ■ cd—Change directory to the home or root Flash directory. ■ copy flash:[filename] tftp:—Copy the file filename from Flash to a TFTP server. The server address and destination filename are prompted. ■ copy tftp: flash:[filename]—Copy a file from the TFTP server into Flash memory. The TFTP server address and any unresolved filenames are prompted. ■ delete flash:filename—The file filename is deleted from Flash memory. ■ erase flash:—All files in Flash memory are erased in one command. ■ format flash:—The Flash file system is reformatted, destroying all existing files. Formatting is appropriate when the Flash memory has been corrupted. You can also manipulate the switch configuration files from privileged EXEC (enable) mode. Remember that two configuration files exist at all times—the running-config and startup-config. Any configuration changes you make to a switch are applied immediately to the running-config file. The only way to update the startup-config is by manually copying another file to it. Cisco IOS Software allows the following commands to manipulate the configuration files: ■ copy running-config startup-config—The contents of the running-config are copied into the startup-config, replacing any similar commands there. After this is done, any dynamic configuration changes are saved and are preserved across power failures or switch reloads. (This command should be used regularly to save any new configuration changes. Use it prudently, if you need to back out a large number of changes.) ■ copy startup-config running-config—The permanent contents of the startup-config file are copied into the running-config, replacing any similar commands there. The entire running- config isn’t simply overwritten; rather, the startup-config commands are copied over while any other existing running-config commands are kept active. This operation is performed as a switch boots up. (This command can quickly restore a misconfigured switch to a known state.) 1-58720-077-5.book Page 95 Tuesday, August 19, 2003 3:16 PM 96 Chapter 4: Switch Configuration ■ copy running-config tftp:—A switch’s current running configuration is copied to a TFTP server. The server address and destination filename are prompted. Use this command to store a backup snapshot copy of the switch configuration. ■ copy tftp: startup-config—When a switch configuration is lost or needs to be restored to a known state, a backup copy of the configuration is copied from a TFTP server to the startup-config file. The new changes won’t take effect until the switch is reloaded, or until the startup-config is copied to the running-config. (You could also use copy tftp: running-config, but this would make immediate configuration changes as commands from the TFTP file are copied over. Use caution so that your configuration changes occur under controlled circumstances.) ■ erase startup-config—The entire contents of the startup-config file are erased. Use this command when a switch has been retired from one function and needs to be relocated or completely reconfigured. Troubleshooting from the Operating System The Cisco Catalyst IOS Software provides many commands that can verify or troubleshoot a switch in its current environment. Sometimes, you might wonder what software image or configuration commands are being used by a switch. A switch can also produce real-time debugging information about a feature or condition to aid in troubleshooting. Information is also available to help identify other neighboring Cisco devices in a network. This section explains each of these tasks and how to accomplish them using the relevant commands. Show Configuration and File Contents Cisco IOS Software offers many commands that you can use from the EXEC mode command line to display the contents of files, current configuration states, and values for troubleshooting. You can use the following commands to view and troubleshoot switch files and file systems: ■ show version—Displays the current version of IOS running in a switch, along with many details about available hardware, RAM and Flash memory, switch uptime, current running IOS image file, reason for the last reload, and the configuration register’s contents. ■ show running-config [interface type mod/num | vlan vlan-id | module mod]—Displays the contents of the running-config configuration file. You can jump to the relevant configuration of a specific interface, VLAN, or switch module, if desired. ■ show startup-config—Displays the startup-config configuration file’s contents. ■ show tech-support—Provides information to Cisco TAC support personnel; almost every known bit of information about the switch is displayed. Be sure to configure your terminal emulator to capture text to a file before issuing this command. 1-58720-077-5.book Page 96 Tuesday, August 19, 2003 3:16 PM Troubleshooting from the Operating System 97 ■ verify flash:filename—Verifies the checksum of the Flash file filename. This can ensure that an IOS image is not corrupted after it has been copied into Flash memory. (During the actual copy process, the checksum is automatically verified. You can use the verify command to make sure the file has not become corrupted since it was originally copied.) ■ more filesystem:filename—Displays the contents of a plain text file from the command line. This can be useful when you need to read configuration files that have been stored in a Flash file system. You can also view text files that are stored on a remote TFTP server—from the IOS command line. Debugging Output For more focused and real-time information about a certain switch feature, you can use the debug EXEC command. Debug output is not normally used, unless you suspect a problem with a feature or an interaction with other switches in the network. You can use many options with the debug command—each pertaining to a switch feature or a specific activity. Type the debug command followed by ? to get context-based help on all the supported debugging commands and keywords. After you enable a debug command, you can see the debug output listed as events can occur on the switch. NOTE You can filter the output of any show command so that you see only lines containing specific keywords. Append the “pipe” symbol (|) to the command line, followed by one of these keywords: begin text (start the output with the line containing text), include text (only display lines that contain text), or exclude text (only display lines that don’t contain text). When a large amount of output is displayed, the switch usually shows a page at a time, pausing with a “-More-” prompt. You can either press the SPACE key to display the next page, the RETURN (Enter) key to display the next line, or /text to search forward and begin the page of output at the line containing text. Using the slash key allows a quick search within the context of the entire output. CAUTION Use the debug commands cautiously because they can generate a tremendous amount of output. Not only can this display slowly on a serial console connection, but also the debug process itself can bog the switch CPU down to the point that it severely impacts traffic forwarding. 1-58720-077-5.book Page 97 Tuesday, August 19, 2003 3:16 PM 98 Chapter 4: Switch Configuration Always be sure to turn off any debugging commands when you finish with them. Do so by using the no debug options command, where the options keywords match the ones you used to enable debugging. To quickly disable all active debugging commands, use the no debug all or undebug all commands. View CDP Information To view information learned from CDP advertisements of neighboring Cisco devices, use one of the following commands: Switch# ss ss hh hh oo oo ww ww cc cc dd dd pp pp ii ii nn nn tt tt ee ee rr rr ff ff aa aa cc cc ee ee [ type mod / num ] Switch# ss ss hh hh oo oo ww ww cc cc dd dd pp pp nn nn ee ee ii ii gg gg hh hh bb bb oo oo rr rr ss ss [ type mod/num | vv vv ll ll aa aa nn nn vlan-id ] [dd dd ee ee tt tt aa aa ii ii ll ll ] The first command displays CDP information pertaining to a specific interface. If the type, module, and port information is omitted, CDP information from all interfaces is listed. The second command displays CDP information about neighboring Cisco devices. A specific interface or VLAN can be given to display only neighbors connected to it. Using the detail keyword results in the display of all possible CDP information about each neighbor. Recall that CDP messages are sent out every 60 seconds, and all entries received are placed in a cache. The cache is updated with new entries, and stale entries are aged out after a hold time of 180 seconds. If you suspect a problem with a neighboring switch, you might want to clear the CDP cache of all potentially state information to see what new information is being received from neighbors. Do this with the clear cdp table command. As demonstrated in Example 4-1, the show cdp neighbors and the show cdp neighbors detail command can be useful when you are connected to a switch and need to know more about what other switches are nearby in a network. Particularly useful are the IP address entries, allowing Telnet access to previously unknown switches. To see a brief listing of only the neighbor switch names and their management IP addresses, use the show cdp entry * protocol command. Example 4-1 Displaying CDP Information for Neighboring Devices Switch# ss ss hh hh oo oo ww ww cc cc dd dd pp pp nn nn ee ee ii ii gg gg hh hh bb bb oo oo rr rr ss ss Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater Device ID Local Intrfce Holdtme Capability Platform Port ID BuildingA-1 Gig 2/1 158 S I WS-C3550-4Gig 0/1 CoreSwitch-1 Gig 1/1 158 T S WS-C6509 4/16 Switch# ss ss hh hh oo oo ww ww cc cc dd dd pp pp nn nn ee ee ii ii gg gg hh hh bb bb oo oo rr rr ss ss gg gg ii ii gg gg 11 11 // // 11 11 dd dd ee ee tt tt aa aa ii ii ll ll Device ID: CoreSwitch-1 Entry address(es): IP address: 192.168.199.9 1-58720-077-5.book Page 98 Tuesday, August 19, 2003 3:16 PM Troubleshooting from the Operating System 99 Platform: WS-C6509, Capabilities: Trans-Bridge Switch Interface: GigabitEthernet1/1, Port ID (outgoing port): 4/16 Holdtime : 130 sec Version : WS-C6509 Software, Version McpSW: 7.2(2) NmpSW: 7.2(2) Copyright (c) 1995-2002 by Cisco Systems advertisement version: 2 VTP Management Domain: 'Core' Switch# ss ss hh hh oo oo ww ww cc cc dd dd pp pp ee ee nn nn tt tt rr rr yy yy ** ** pp pp rr rr oo oo tt tt oo oo cc cc oo oo ll ll Protocol information for BuildingA-1 : IP address: 192.168.199.107 Protocol information for CoreSwitch-1 : IP address: 192.168.199.9 Switch# Example 4-1 Displaying CDP Information for Neighboring Devices (Continued) 1-58720-077-5.book Page 99 Tuesday, August 19, 2003 3:16 PM 100 Chapter 4: Switch Configuration Foundation Summary The Foundation Summary is a collection of tables that provides a convenient review of many key concepts in this chapter. If you are already comfortable with the topics in this chapter, this summary can help you recall a few details. If you just read this chapter, this review should help solidify some key facts. If you are doing your final preparation before the exam, the following tables are a convenient way to review the day before the exam. Table 4-3 Switch Management Configuration Commands Task Command Syntax Identify switch hostname hostname Set EXEC level password line type number password password Set privileged level password enable secret password Set IP address interface vlan vlan-id ip address ip-address netmask ip default-gateway ip-address CDP (default is enabled on every switch port) cdp enable Table 4-4 File Management Commands Task Command Syntax Directory of Flash dir [flash:[directory]] Change directory cd flash:directory Copy a file between Flash and a TFTP server copy flash:[filename] tftp: -OR- copy tftp: flash:[filename] Delete a file in Flash delete flash:filename 1-58720-077-5.book Page 100 Tuesday, August 19, 2003 3:16 PM Foundation Summary 101 Clear Flash contents erase flash: -OR- format flash: Save the running configuration copy running-config startup-config -OR- copy running-config tftp: Overwrite the running configuration copy startup-config running-config Overwrite the permanent configuration copy tftp: startup-config -OR- erase startup-config Table 4-5 Troubleshooting Commands Task Command Syntax Display the current running environment and IOS version show version Display the running configuration show running-config [interface type mod/num | vlan vlan-id | module mod] Display the permanent configuration show startup-config -OR- show config Display all technical support information show tech-support Verify an image checksum verify flash:filename continues Table 4-4 File Management Commands (Continued) Task Command Syntax 1-58720-077-5.book Page 101 Tuesday, August 19, 2003 3:16 PM 102 Chapter 4: Switch Configuration Enable or disable debugging debug keywords no debug keywords -OR- no debug all -OR- undebug all Display CDP information show cdp interface [type mod/num] -OR- show cdp neighbors [type mod/num | vlan vlan-id] [detail] -OR- show cdp entry * protocol Table 4-5 Troubleshooting Commands (Continued) Task Command Syntax 1-58720-077-5.book Page 102 Tuesday, August 19, 2003 3:16 PM [...]... same speed and duplex 1-58720-077-5.book Page 128 Tuesday, August 19, 20 03 3:16 PM 128 Chapter 5: Switch Port Configuration Example 5-2 Determining Link Speed and Duplex Mode switch# show interface fastethernet 0/ 13 FastEthernet0/ 13 is up, line protocol is up Hardware is Fast Ethernet, address is 00d0.589c.3e8d (bia 00d0.589c.3e8d) MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, reliability 255/255,... same? a b Layer 2 c Layer 3 d 3 Layer 1 Layer 4 At what layer are traditional 10 Mbps Ethernet, Fast Ethernet, and Gigabit Ethernet different? a Layer 1 b Layer 2 c Layer 3 d Layer 4 1-58720-077-5.book Page 109 Tuesday, August 19, 20 03 3:16 PM ”Do I Know This Already?” Quiz 4 What is the maximum cable distance for a Category 5 100BASE-TX connection? a 100 feet b 100 meters c 32 8 meters d 5 500 meters... only a LAN PHY 1-58720-077-5.book Page 119 Tuesday, August 19, 20 03 3:16 PM Ethernet Concepts 119 10Gigabit Ethernet PMD Types and Characteristics Table 5-5 PMD type1 Maximum Distance Catalyst Switch 10GBASE-SR/SW (850 nm serial) MMF: 50 micron 66 m N/A MMF: 50 micron (2GHz * km modal bandwidth) 30 0 m MMF: 62.5 micron 33 m 10GBASE-LR/LW ( 131 0 nm serial) SMF: 9 micron 10 km Catalyst 6500 10GBASE-ER/EW...1-58720-077-5.book Page 1 03 Tuesday, August 19, 20 03 3:16 PM Q&A 1 03 Q&A The questions and scenarios in this book are more difficult than what you should experience on the actual exam The questions do not attempt to cover more breadth or depth than the exam; however, they are designed to make sure that you know the answer Rather than allowing... 850 nm laser 1 550 m MMF with 62.5 micron core; 130 0 nm laser 1 550 m Single-mode fiber (SMF) with 50 micron core; 130 0 nm laser 1 550 m SMF with 9 micron core; 130 0 nm laser 1 10 km SMF with 9 micron core; 1550 nm laser 1 70 km SMF with 8 micron core; 1550 nm laser 1 100 km 1000BASE-LX/LH 1000BASE-ZX 1-58720-077-5.book Page 118 Tuesday, August 19, 20 03 3:16 PM 118 Chapter 5: Switch Port Configuration... debugging output? 18 What command can you use to verify CDP configuration on switch port GigabitEthernet 3/ 1? 1-58720-077-5.book Page 106 Tuesday, August 19, 20 03 3:16 PM This chapter covers the following topics that you need to master for the CCNP BCMSN exam: I Ethernet Concepts—This section discusses the concepts and technology behind various forms of Ethernet media Ethernet solutions for service providers,... If any errdisable causes are configured for automatic recovery, the errdisabled port stays down for 30 0 seconds, by default To change the recovery timer, use the following command in global configuration mode: Switch(config)# errdisable recovery interval seconds You can set the interval from 30 to 86,400 seconds (24 hours) Enable and Use the Switch Port If the port is not automatically enabled or activated,... techniques 1-58720-077-5.book Page 127 Tuesday, August 19, 20 03 3:16 PM Switch Port Configuration 127 Looking for the Port State Use the show interface EXEC command to see complete information about the switch port The port’s current state is given in the first line of output, as in Example 5-1 Example 5-1 Determining Port State Information sbrn- 437 -c1# show interface fastethernet 0/1 FastEthernet0/1 is... to VLAN 1 so that no link is in trunking mode On one of the access switches, how many neighboring switches will be shown by the show cdp neighbor gigabit 0/1? 13 Which IOS image file is more recent: c3550-i5q3l2-mz.121-12c.EA1.bin or c3550-i9q3l2-mz.121-11c.EA1.bin? 14 A new switch has just been configured with 100 command lines from the console You realize the need to save the new configuration and type... packets/sec 500867 packets input, 89215950 bytes Received 12912 broadcasts, 37 4879 runts, 0 giants, 0 throttles runts 37 4879 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored errors 0 watchdog, 0 multicast 0 input packets with dribble condition detected 8967 238 8 packets output, 22054 437 29 bytes, 0 underruns 0 output errors, 0 collisions, 3 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, . port GigabitEthernet 3/ 1? 1-58720-077-5.book Page 105 Tuesday, August 19, 20 03 3:16 PM This chapter covers the following topics that you need to master for the CCNP BCMSN exam: ■ Ethernet Concepts—This. will be shown by the show cdp neighbor gigabit 0/1? 13. Which IOS image file is more recent: c3550-i5q3l2-mz.121-12c.EA1.bin or c3550-i9q3l2-mz.121-11c.EA1.bin? 14. A new switch has just been. 102 Tuesday, August 19, 20 03 3:16 PM Q&A 1 03 Q&A The questions and scenarios in this book are more difficult than what you should experience on the actual exam. The questions do not attempt