Juniper JNCIA-Junos - Operational Monitoring and Maintenance

For the last chapter of Juniper’s first PDF, we are going to have a closer look how to get more information about JunOS and also practice the password recovery procedure that will sooner and later be useful for you.

Exercise 1 – boot messages

Do you remember the booting process in chapter 1? Well you have a command to see the messages again (hint: use the show system command).

Solution

root@JUNOS1# run show system boot-messages
Copyright (c) 1996-2010, Juniper Networks, Inc.
...
ad1: 1024MB <QEMU HARDDISK 0.11.0> at ata0-slave WDMA2
Trying to mount root from ufs:/dev/ad0s1a
vn_read_compressed_block: invalid block index 550

Exercise 2 – JunOS packages

Still about the booting process, we have seen that JunOS packages are loaded on virtual memory disks (you can still see that using the show system storage command). Find the command which list all these packages including their versions.

Solution

root@JUNOS1> show version
Hostname: JUNOS1
Model: olive
JUNOS Base OS boot [10.1R1.8]
JUNOS Base OS Software Suite [10.1R1.8]
JUNOS AppId Services [10.1R1.8]
JUNOS IDP Services [10.1R1.8]
JUNOS Routing Software Suite [10.1R1.8]

Exercise 3 – network interfaces

Now show all interfaces configured on JUNOS1 (equivalent to show ip interface brief on Cisco IOS) and then use a command to show a maximum of details for interface em0.

Solution

root@JUNOS1> show interfaces terse
Interface               Admin Link Proto    Local                 Remote
em0                     up    up
em0.0                   up    up   inet     192.168.1.1/24
192.168.1.3/24
...

root@JUNOS1> show interfaces em0 extensive
Physical interface: em0, Enabled, Physical link is Up
Interface index: 8, SNMP ifIndex: 17, Generation: 134
Type: Ethernet, Link-level type: Ethernet, MTU: 1514, Clocking:
...

Exercise 4 – monitor

Let’s play a bit more with the monitor command. On JUNOS2, monitor all interface traffic (statistics) in real time. From JUNOS1 ping JUNOS2 (192.168.1.2) and check the counters incrementing.

Solution

root@JUNOS2> monitor interface traffic
Interface    Link  Input packets        (pps)     Output packets        (pps)
...
em0           Up           1476                            1302
...

Exercise 5 – password recovery

Now assume you have forgotten the root password for JUNOS2 or maybe you really have, don’t panic, you are going to do a password recovery. First reboot you system and be ready to hit space to get to the kernel command prompt. Then follow the procedure as explained in the documentation.

root@JUNOS2> request system reboot
Reboot the system ? [yes,no] (no) yes
...

Solution

Hit [Enter] to boot immediately, or space bar for command prompt.
<space>
Type '?' for a list of commands, 'help' for more detailed help.
OK boot –s
...
Enter full pathname of shell or 'recovery' for root password recovery or RETURN for /bin/sh: recovery
...
NOTE: Once in the CLI, you will need to enter configuration mode using
NOTE: the 'configure' command to make any required changes. For example,
NOTE: to reset the root password, type:
NOTE:    configure
NOTE:    set system root-authentication plain-text-password
NOTE:    (enter the new password when asked)
NOTE:    commit
NOTE:    exit
NOTE:    exit
NOTE: When you exit the CLI, you will be asked if you want to reboot
NOTE: the system

Starting CLI ...
root> configure
Entering configuration mode

[edit]
root# set system root-authentication plain-text-password
New password:
Retype new password:

[edit]
root# commit
error: could not open database: /var/run/db/juniper.data: No such file or directory
error: Database open failed for file '/var/run/db/juniper.data': No such file or directory
commit complete

[edit]
root@JUNOS2# exit
Exiting configuration mode

root@JUNOS2> exit
Reboot the system? [y/n] y

Well done, you completed all exercises for Juniper’s first PDF, now it is time to go into more serious stuff with the second PDF and Routing Fundamentals