Juniper Trouble Shooting

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Juniper M, T and MX trouble shooting tips and real world cases

Text of Juniper Trouble Shooting

  • 1.Control and Forwarding plane
    • Synchronization
  • 100-Mbpsfxp1Ethernet link is used between RE and PFE
  • For M320 case, 100-Mbps Ethernet switch is being used to provide a dedicated link to each FPC. For RE, these links are presented atbcm0
  • Fxp0: management interface
  • Fxp2: communication between Primary RE and backup RE
  • 3)Forwarding table (FT) can hold over 800,000 routes.

2. Difference between M7i and M10i

  • Redundant RE: M10i support, not M7i
  • Built-in Adaptive Service: M7i. M10i needs an external AS PIC.
  • RE: the same

3. System storage

  • 3 types of storages:
  • Compact Flash(ad0) : built-in at the board.
  • Hard Drive(ad1)
  • External storage
  • -PCMCIA card(da0??)
  • -USB(da1??)

4. JUNOS CLI basics

  • Space bar to complete a command
  • Command:Help topic for general concepts
  • Command : help reference for configuration syntax
  • Rebooting system:request system reboot
  • Shut down system:request system halt
  • Log and Trace files are located at /var/log
  • Command:Show log | messages |file-name
  • At more prompt, use forward slash(/) to search or use h to get a context help screen
  • Log commands examples:
  • - show log messages | match so-0/3/1 | match TRAP--- AND --
  • - show log messages | mach fpc | sfm | kernel--- OR ---
  • Monitor log/trace in real time:monitor startfile-name| match fail
  • Stop monitoring in real time:monitor stop
  • Enable/disable real-time output to screen: Esc-Q
  • Stop traceing operation:delete flag open
  • Truncate(clear) log/trace files:clear logfile-name
  • Delete log/trace files:file deletefile-name

5. JUNOS CLI basics

  • Entering configuration:Typeconfigureoredit
  • Exclusive configuration (configure exclusive) and Private configuration (configure private??)
  • Moving within the configuration hierarchy: edit (equivalent to cd), up, top, exit (to previous location in the hierarchy)
  • Show command at configuration mode vs. show command at operational-mode
  • Relative configuration commands Starting with JUNOS5.3 : top
  • - top show system login(show system login no matter where you are.Examples:
  • - top edit protocols ospf( to enter protocols ospf no matter where you are)
  • Viewing configuration in operational mode:show configuration < configuration path>
  • View configuration with set: show xxx | display set
  • Viewing candidate configuration: show chassis alarm,show (at the current sub-hierarchy)

6. JUNOS CLI basics

  • Change the candidate configuration. Examples:
  • - set alarm sonet lol red
  • - delete alarm sonet pll
  • Display difference between the candidate and active configurations:
  • At the current statement-path, show | compare
  • Viewing difference in files. Example:
  • - file showfilename1| compare filefilename2
  • - show configuarion | compare rollback number
  • Removing statements:delete
  • Delete the statements and all its subordinate statements and identifieres.
  • Wildcard delete. Example:wildcard delte interfaces fe-*
  • Ignore portion of the configuration hierarchy:deactivate/activate
  • Disable an interface: set disable interface
  • Delete and disabled interface: delete interface disable

7. JUNOS CLI basics

  • Activate a configuration
  • commit ----- candidate file is checked, actived and marked as the current
  • operational sofware configuration file.
  • commit check ----- only validate a candidate configuration without
  • placing it into effect.
  • rollback n -------- recover the previous configuration. And then commit
  • rollback 0is current configuration
  • First 3 roll back (1-3) are stored in solid-state flash disk
  • /config/juniper.conf.n (n=1-3)
  • rest roll back (4-49) are stored in hard disk/var/db/config
  • commit confirmedtime-out---- temporarily activate a configuration (default is 10 minutes). If the final commit is not executed, the system will performs a rollback 1, commit commands.
  • commit synchronize ---- after committed on the master RE internally
  • copied and committed on the backup RE automatically.
  • commit attime----- commit at some time
  • clear system commit ---- cancel a pending commit

8. JUNOS CLI basics

  • Save a configuration
  • savefilename
  • save terminal-- for copy and paste into other others
  • show | display set create configuration for simplifying configuration editing.
  • Loading configuration files ( load and then commit)
  • load override filenameoverride the currentconfig with the loaded one. Do it at the root of the configuration hierarchy.
  • load mergefilename - combine the new and old
  • load merge terminal(then copy/paste hierarchical configuration)
  • load replacefilename statements with replace tag will replace the statements with the same name
  • load relativeload at where it is current at the configuration hierarchy.

9. Junos CLI Basics

  • Only save the configuration under certain hierarchy. To save the whole configure, issue this command at the top of the hierarchy.
  • # Save
  • Display the contents of the file you saved
  • # Run file show
  • To load a configuration after clear the current configuration
  • # delete
  • #show
  • #load override
  • To recover a mistake made previously after committing.
  • #rollback 1

10. Junos CLI Basics

  • show log messages | last
  • Show log interactive-commands | match restart
  • Use sysctl a to display kernel parameters.
  • sysctl a | grep icmp(under shell prompt)
  • show chassis 0 pic slot 1 information.
  • Show chassis pic fpc-slot 0 pic-slot 1
  • Master switchover
  • Request chassis cfeb master switch
  • Request chassis routing-engine master switch

11. Junos CLI Basics

  • Find out who logins the system and kick out some particular users.
  • show system users
  • reequest system logout
  • help syslog
  • Example:
  • lab@santro-re0> help syslog ACCT_ACCOUNTING_FERROR
  • Message:Unexpected error from file
  • Help:Error occurred during file processing
  • Description:An error prevented the accounting statistics process from processing the indicated file.
  • Type:Error: An error occurred
  • Severity:warning

12. Junos CLI Basic

  • show configuration with inheritance
  • show configuration interfaces ge-4/3/3 | displayinheritance

13. Syslog

  • set system syslog file messages any notice

14. Hardware troubleshooting process

  • Show chassis alarms
  • Show chassis craft-interface
  • Show log messages
  • Show log chassid
  • Monitor start [message | chassid]
  • Show chassis hardware
  • Show chassis fpc
  • Show pfe stat error
  • Show interface terse
  • Show interface detail
  • Show log

15. Display PIC status

  • Show chassis pic fpc-slot 0 pic-slot 1
  • Example:
  • lab@santro-re0> show chassis pic fpc-slot 0 pic-slot 1
  • FPC slot 0, PIC slot 1 information:
  • Type10x 1GE(LAN), 1000 BASE
  • ASIC typeH chip
  • StateOnline
  • PIC version1.13
  • Uptime1 day, 22 hours, 25 minutes, 17 seconds
  • PIC port information:
  • FiberXcvr vendor
  • PortCable typetypeXcvr vendorpart numberWavelength

16. Boot image

  • If you need to reboot from PCMCIA card, you need to copy a special image called jinstall-mediaxxxx .
  • Interrupt normal boot
  • Hit space when the system is rebooting until it goes to either boot: or OK prompt.
  • If you get boot: prompt, the loader is not run yet. You need to do this:
  • Boot: /boot/loader
  • Change a boot device at OK prompt
  • Ok nextboot compact-flash
  • Ok reboot

17. Interfaces