Using Debug Commands on Cisco IOS XR Software

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Using Debug Commands on Cisco IOS XR Software This document describes how to use the Cisco IOS XR software debug commands to monitor system operations and troubleshoot errors.

1 Using Debug Commands on Cisco IOS XR Software This document describes how to use the Cisco IOS XR software debug commands to monitor system operations and troubleshoot errors. Contents Listing Available Debug Commands, page 2 Usage Guidelines, page 3 Enabling and Disabling Debug Commands, page 4 Viewing Debug Information in the Trace Buffer, page 6 Redirecting debug and Error Message Output, page 6 Additional References, page 10 UDB-1

2 Listing Available Debug Commands Listing Available Debug Commands To display a complete list of debug commands available on Cisco IOS XR software as well as a short description of each command, enter the debug command and type a? question mark at the prompt. For example: RP/0/RP0/CPU0:router# debug RP/0/RP0/CPU0:router(debug)#? aaa adjacency aib alarm-logger arm arp asic-scan async attribute auto-rp avl bambi bcdl bfd bfm bgp bundlemgr cctl-spa cdp cef cetftp chdlc check-consistency --More AAA Authentication, Authorization and Accounting platform AIB information AIB information Turn on alarm debugging IP Address Repository Manager IP ARP transactions Debug Asic Scan async messaging information IM Attributes debug commands debug auto-rp Debug avl commands Debug PLIM LINK ASIC Bulk Content DownLoader information Bidirectional Forwarding Detection Debug Buffer Manager Server BGP debug commands Bundle Manager debug commands Debug the functionality of SPA Chassis Control Server CDP information IP CEF commands cetftp debug: Debug the functionality of CE-TFTP Server chdlc Information Debug Route Consistency Checker Note For detailed information about using the CLI, see the section entitled CLI Tips, Techniques, and Shortcuts in the Cisco IOS XR Getting Started Guide. Note Not all debugging commands listed in the debug? command output are documented in the Cisco IOS XR documentation. Commands not included are typically used only by Cisco engineers during software development and are unintended for use in the field. Commands are documented based on their diagnostic value. UDB-2

3 Usage Guidelines Usage Guidelines The sections that follow describe some of the usage guidelines when using debug commands on Cisco IOS XR software. System Performance Impact Debugging output is assigned high priority in the CPU process and can affect system performance. For this reason, use debug commands only to troubleshoot specific problems or during troubleshooting sessions with Cisco technical support staff. Furthermore, we recommend that you use debug commands during periods of lighter network traffic. Command Modes You can enter debug commands from any of the modes or submodes described in Table 2. Table 2 Debug command modes and submodes Mode or Sub-Mode EXEC (mode) EXEC debug (sub-mode) Admin EXEC (mode) Undebug (mode) Description The default command mode for the CLI. To enter debug commands in EXEC mode, type: RP/0/RP0/CPU0:router# debug mpls ldp config From this submode, you can enter debug commands directly. To enter EXEC debug mode, type: RP/0/RP0/CPU0:router# debug RP/0/RP0/CPU0:router(debug)# mpls ldp config The admin EXEC mode applies to logical routers (LRs). With configured logical routers, the EXEC mode provides visibility to only one logical router at a time. You must enter administration EXEC mode to affect all system parameters. To enter admin EXEC mode, type: RP/0/RP0/CPU0:router# admin RP/0/RP0/CPU0:router(admin)# debug mpls ldp config From this mode, you can enter commands directly. To enter undebug mode, type: RP/0/RP0/CPU0:router# debug RP/0/RP0/CPU0:router(debug)# mpls ldp config Command modes and sub-modes used with debug commands. For more information about command modes in Cisco IOS XR software, see the Cisco IOS XR Command Modes Descriptions document online at UDB-3

4 Enabling and Disabling Debug Commands Enabling and Disabling Debug Commands The sections that follow describe how to enable and disable debug commands. Enabling Debug Commands You can enter a debug command from any of the modes or sub-modes described in Table 2. After you enter a debug command, the output continues unabated until the debug command is disabled. There are several ways to stop a command or series of debug commands as described in Disabling Debug Commands, page 5. The following is sample output from the debug mpls ldp config command run from EXEC mode: RP/0/RP0/CPU0:router# debug mpls ldp config RP/0/RP0/CPU0:router# RP/0/RP0/CPU0:Aug 5 07:18:14.397: mpls_ldp[315]: DBG-Config: LDP GR cfg read: in_use=no, cfged=no RP/0/RP0/CPU0:Aug 5 07:18:16.782: mpls_ldp[315]: DBG-Config: BACKEND_SCAN: global-section (/cfg/gl/mpls_ldp/ord_gl/) RP/0/RP0/CPU0:Aug 5 07:18:16.793: mpls_ldp[315]: DBG-Config: ldp_router_id_apply: Unpacked tuple: mask 0x3, cmd 1, new_ifname Loopback0 ipaddr 0 RP/0/RP0/CPU0:Aug 5 07:18:16.793: mpls_ldp[315]: DBG-Config: CREATE/SET: item='ord_gl/aa/router-id' RP/0/RP0/CPU0:Aug 5 07:18:16.793: mpls_ldp[315]: DBG-Config: intf=loopback0, Not yet CREATed in our db - processing IFRS RP/0/RP0/CPU0:Aug 5 07:18:16.794: mpls_ldp[315]: DBG-Config: ldp_add_tuple_for_ifrs: intf=loopback0, tuple='ord_gl/aa/router-id' RP/0/RP0/CPU0:Aug 5 07:18:16.794: mpls_ldp[315]: DBG-Config: intf=loopback0, Not in IFRS - adding entry RP/0/RP0/CPU0:Aug 5 07:18:16.796: mpls_ldp[315]: DBG-Config: BACKEND_SCAN: if-section (/cfg/gl/mpls_ldp/ord_if/) RP/0/RP0/CPU0:Aug 5 07:18:16.797: mpls_ldp[315]: DBG-Config: CREATE/SET: item='ord_if/if/gigabitethernet0_3_0_0/ipv4' RP/0/RP0/CPU0:Aug 5 07:18:16.797: mpls_ldp[315]: DBG-Config: intf=gigabitethernet0_3_0_0, Not yet created in our db - processing IFRS... If you enable a debug command and no output is displayed, consider the following possibilities: The router may not be properly configured to generate the type of traffic you want to monitor. Use the more system:running-config EXEC command to check its configuration. Even if the router is properly configured, it may not generate the type of traffic you want to monitor during the particular period that debugging is turned on. Depending on the protocol you are debugging, you can use commands such as the TCP/IP ping EXEC command to generate network traffic. You may not have the proper logging level enabled for the session or logging facility you are using to monitor the debug output. UDB-4

5 Verifying Debug Command Status using Show Commands Disabling Debug Commands The router generates debug output until you stop the command from running. There are several ways you can stop the debug output. You can enter the no form of the command from EXEC mode, for example: RP/0/RP0/CPU0:router# no debug mpls ldp config You can enter undebug sub-mode and enter the debug command name, for example: RP/0/RP0/CPU0:router# undebug RP/0/RP0/CPU0:router(undebug)# mpls ldp config Note For each debug command in Cisco IOS XR software there is an undebug command. You can run the no debug all-tty debug command, for example: RP/0/RP0/CPU0:router# no debug all-tty Verifying Debug Command Status using Show Commands You can enter two different commands to display the enabled or disabled state of each debug command, as follows: debug command name config, for example: RP/0/RP0/CPU0:router# debug mpls ldp config Neighbors: 2 (0 Targeted, 2 Graceful Restartable) Known Routes: 11 Installed forwarding rewrites: 3 Local addresses: 4 Known interfaces: 4 (2 LDP enabled) Clients: 0 Servers: Connected Registered SysDB Y Y IM Y Y IP ARM Y - LSD Y Y FIBv4 Y Y show debug?, for example: RP/0/RP0/CPU0:router# show debug? WORD Show debug commands for the given branch enabled from this TTY all-tty Show debug commands enabled from all TTYs conditions Show debug conditions enabled from this tty location Specify a location tty-mnemonic Show debug commands enabled from this tty-mnemonic Output Modifiers UDB-5

6 Viewing Debug Information in the Trace Buffer To show debug processes for your local tty session, use the show debug command, for example: RP/0/RP0/CPU0:router# show debug #### debug flags set from tty 'vty2' #### mpls_ldp config flag is ON To show show all debug processes running on the router, use the show debug all-tty command, for example: RP/0/RP0/CPU0:router# show debug all-tty #### debug flags set from tty 'vty3' #### ipv4 rib routing flag is ON #### debug flags set from tty 'vty2' #### mpls_ldp config flag is ON Viewing Debug Information in the Trace Buffer Cisco IOS XR software lets you use the show command trace keyword to view debug information in the trace buffer. The following example shows sample output for the show rib trace command: RP/0/RP0/CPU0:CRS-A_IOX#show rib trace 4821 wrapping entries (13312 possible, 0 filtered, total) Aug 26 14:42: rib/ipv4_rib/rib-startup 0/RP0/CPU0 t1 Create: Management thread Aug 26 14:42: rib/ipv4_rib/rib-startup 0/RP0/CPU0 t2 Create: Management event manager Aug 26 14:42: rib/ipv4_rib/rib-startup 0/RP0/CPU0 t2 Initialise: Debugging routine Aug 26 14:42: rib/ipv4_rib/rib-startup 0/RP0/CPU0 t1 Register: cerrno DLL name lib_rib_error.dll Aug 26 14:42: rib/ipv4_rib/rib-startup 0/RP0/CPU0 t2 Initialise: EDM routine Aug 26 14:42: rib/ipv4_rib/rib-startup 0/RP0/CPU0 t1 Create: default unicast/multicast tables Aug 26 14:42: rib/ipv4_rib/rib-startup 0/RP0/CPU0 t1 Create: Default table, table 17, afi 1, safi 1 Aug 26 14:42: rib/ipv4_rib/rib-sync 0/RP0/CPU0 t1 Sync (17): Out of sync Aug 26 14:42: rib/ipv4_rib/rib-startup 0/RP0/CPU0 t1 Sysmgr node state query: SUCCESS: 1=Active Aug 26 14:42: rib/ipv4_rib/rib-startup 0/RP0/CPU0 t1 Create: Default table, table 18, afi 1, safi 2 Note Trace runs in the background and requires very minimal CPU time. Redirecting debug and Error Message Output By default, the network server sends the output from debug commands and system error messages to the console. If you choose the default functionality, monitor debug output using a virtual terminal connection instead of the console port. To redirect debug output, use the logging command options within configuration mode as described in the following sections. Possible destinations include the console, virtual terminals, internal buffer, and UNIX hosts running a syslog server. The syslog format is compatible with 4.3 Berkeley Standard Distribution (BSD) UNIX and its derivatives UDB-6

7 Redirecting debug and Error Message Output Note The debugging destination used affects system overhead. Logging to the console produces very high overhead; logging to a virtual terminal produces less overhead. Logging to a syslog server produces even less, and logging to an internal buffer produces the least overhead of any method. Enabling Message Logging To enable message logging to all supported destinations other than the console, enter the following command: logging on The default condition is logging on. To direct logging to the console only and disable logging output to other destinations, enter the following command: no logging on Setting the Message Logging Level You can set the logging levels when logging messages to the following devices: Console Monitor Syslog server Table 3 lists and briefly describes the logging levels and corresponding keywords you can use to set the logging levels for these types of messages. The highest level of message is level 0, emergencies. The lowest level is level 7, debugging, which also displays the greatest amount of messages. For information about limiting these messages, see sections later in this chapter. Table 3 Message Logging Keywords and Levels Level Keyword Description Syslog Definition 0 emergencies System is unusable. LOG_EMERG 1 alerts Immediate action is needed. LOG_ALERT 2 critical Critical conditions exist. LOG_CRIT 3 errors Error conditions exist. LOG_ERR 4 warnings Warning conditions exist. LOG_WARNING 5 notification Normal, but significant, conditions LOG_NOTICE exist. 6 informational Informational messages. LOG_INFO 7 debugging Debugging messages. LOG_DEBUG UDB-7

8 Redirecting debug and Error Message Output Limiting the Types of Logging Messages Sent to the Console To limit the types of messages logged to the console, use the logging console command. The logging console command limits the logging messages displayed on the console to messages up to and including the specified severity level, which is specified by the level argument. Keywords are listed in order from the most severe level to the least severe. The following example sets console logging of messages at the debugging level, which is the least severe level and which displays all logging messages: RP/0/RP0/CPU0:router# logging console debugging Use the no logging console command to disable logging to the console. Logging Messages to an Internal Buffer Unless otherwise specified, the default logging device is the console. To log messages to an internal buffer, use the logging buffered router configuration command. The full syntax of this command follows: logging buffered no logging buffered The logging buffered command copies logging messages to an internal buffer instead of the console with newer messages overwriting the older messages. To display messages logged in the buffer, use the show logging command. The first message displayed is the oldest message in the buffer. By default, the no logging buffered command cancels the use of the buffer and writes messages to the console. Limiting the Types of Logging Messages Sent to Another Monitor To limit the level of messages logged to the terminal lines (monitors), use the logging monitor router configuration command. The full syntax of this command follows: logging monitor level no logging monitor The logging monitor command limits the logging messages displayed on terminal lines other than the console line to messages with a level up to and including the specified level argument. To display logging messages on a terminal (virtual console), use the terminal monitor EXEC command. The no logging monitor command disables logging to terminal lines other than the console line. The following example sets the level of messages displayed on monitors other than the console to notification: RP/0/RP0/CPU0:router# logging monitor notification UDB-8

9 Redirecting debug and Error Message Output Logging Messages to a UNIX Syslog Server To log messages to a syslog server host, use the logging host global configuration command. The full syntax of this command follows: logging host {ip-address host-name} [xml] no logging host {ip-address host-name} [xml] The logging host command identifies a syslog server host that is to receive logging messages. The ip-address argument is the IP address of the host. By issuing this command more than once, you can build a list of syslog servers that receive logging messages. The no logging host command deletes the syslog server with the specified address from the list of syslogs. Limiting Messages to a Syslog Server To limit the number of messages sent to syslog servers, use the logging trap router configuration command. The full syntax of this command follows: logging trap level no logging trap The logging trap command limits the logging messages sent to syslog servers to logging messages with a level up to and including the specified level argument. To send logging messages to a syslog server, specify its host address with the logging host command. The default trap level is informational. The no logging trap command returns the trap level to the default. Cisco IOS XR software generates the following categories of syslog messages: Error messages at the emergencies level. Error messages at the alerts level. Error messages at the critical level. Error messages about software or hardware malfunctions, displayed at the errors level. Interface up/down transitions and system restart messages, displayed at the notification level. Reload requests and low-process stack messages, displayed at the informational level. Output from the debug commands, displayed at the debugging level. The show logging EXEC command displays the addresses and levels associated with the current logging setup. The command output also includes ancillary statistics. Example of Setting Up a UNIX Syslog Daemon To set up the syslog daemon on a 4.3 BSD UNIX system, include a line such as the following in the file /etc/syslog.conf: local7.debugging /usr/adm/logs/tiplog The local7 keyword specifies the logging facility to be used. UDB-9

10 Additional References The debugging keyword specifies the syslog level. See Table 3 for other keywords that can be used. The UNIX system sends messages at or above the selected debug level to the specified file, in this case /usr/adm/logs/tiplog. The file must already exist, and the syslog daemon must have permission to write to it. For the System V UNIX systems, the line should read as follows: local7.debug /usr/admin/logs/cisco.log Additional References The following section provides references related to using debug commands: Related Documents Related Topic CLI Tips, Techniques, and Shortcuts section in the Carrier Routing System (Cisco CRS-1) router getting started material Cisco IOS XR commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples for all major technology areas. Cisco IOS XR debug commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples for all major technology areas. Command and configuration modes used in the Cisco IOS XR command line interface (CLI) Document Title Cisco IOS XR Getting Started Guide, Release 3.2 Cisco IOS XR Modular Quality of Service Guide, Release 3.2 Cisco IOS XR IP Addresses and Services Guide, Release 3.2 Cisco IOS XR Interface and Hardware Guide, Release 3.2 Cisco IOS XR Multicast Guide, Release 3.2 Cisco IOS XR MPLS Guide, Release 3.2 Cisco IOS XR Routing Guide, Release 3.2 Cisco IOS XR System Security Guide, Release 3.2 Cisco IOS XR System Management Guide, Release 3.2 Cisco IOS XR Modular Quality of Service Debug Guide, Release 3.2 Cisco IOS XR IP Addresses and Services Debug Guide, Release 3.2 Cisco IOS XR Interface and Hardware Debug Guide, Release 3.2 Cisco IOS XR Multicast Debug Guide, Release 3.2 Cisco IOS XR MPLS Debug Guide, Release 3.2 Cisco IOS XR Routing Debug Guide, Release 3.2 Cisco IOS XR System Security Debug Guide, Release 3.2 Cisco IOS XR System Management Debug Guide, Release 3.2 Cisco IOS XR Command Mode Descriptions, Release /cmd_32/index.htm UDB-10

Using Debug Commands

Using Debug Commands This chapter explains how you use debug commands to diagnose and resolve internetworking problems. Specifically, it covers the following topics: Entering debug commands Using the debug?