Introduction to Junos Operating System

As most of us start learning Juniper after getting bit expert with Cisco IOS, and always try to find some relation between two, at least me always does, it gives me couple of advantage knowing that particular thing can be done in both and easy to remember. As this post is just a Intro to Junos OS so I will not get deeper just keep it simple.

Like Cisco IOS when we access it through Console or telnet it gives us the prompt with > sign which means user mode where we run some Show commands and than in order to proceed more verification and configuration command we have to get in to user privilege mode and than in global.

Junos OS start with something called shell mode which looks like unix shell command line. And you have to type cli to get into Junos CLI.

root@% cli
root>

And when you get into Junos CLI prompt end with > which means its is operational mode. In this mode you cannot do configuration but you can perform some verification tasks. Unlike Cisco, Juniper provide help from any mode, with help along with command you looking to know more. 

root> ?
Possible completions:
  clear                Clear information in the system
  configure            Manipulate software configuration information
  file                 Perform file operations
  help                 Provide help information
  monitor              Show real-time debugging information
  mtrace               Trace multicast path from source to receiver
  op                   Invoke an operation script
  ping                 Ping remote target
  quit                 Exit the management session
  request              Make system-level requests
  restart              Restart software process
  set                  Set CLI properties, date/time, craft interface message
  show                 Show system information
  ssh                  Start secure shell on another host
  start                Start shell
  telnet               Telnet to another host
  test                 Perform diagnostic debugging
  traceroute           Trace route to remote ho

root> help topic ospf route-type-community

 

              Configuring OSPF Domain IDs for VPNs

For most OSPF or OSPFv3 configurations involving Layer 3 VPNs, you do not need to configure an OSPF domain ID. However, for a Layer 3 VPN connecting multiple OSPF or OSPFv3 domains, configuring domain IDs can help you control LSA translation (for Type 3 and Type 5 LSAs) between the OSPF domains and back-door paths. The default domain ID is 0.0.0.0. Each VPN routing table in a PE router associated with an OSPF or OSPFv3 instance is configured with the same OSPF domain ID.

In order to perform some configuration you have to get into  configuration mode by typing configure.

root> configure
Entering configuration mode

[edit]
root#

# mean you are in configuration mode. From here you can go further configure particular setting. For that you dig in to the particular setting and than configure or sitting at top level of the hierarchy and give full path in the command line. 

Lets say you want to set new user name one way doing is to execute command from the top level.

root# set system login user lab1 class operator authentication

[edit]

Below another user account is created but first getting into to system login and than creating user.

[edit]
root# edit system login

[edit system login]
root# set user lab2 class operator

[edit system login]
root# set user lab2 authentication plain-text-password

This is how Junos has it OS operating in all of it platforms, in hierarchical order.

Real Equipments or Olive (Jonus Emulation)

With any learning journey related to technology there is no two thoughts about the importance of hands-on lab. And all the time it boils down to the cost of having own home labs, if you are working in environment where can get few spare its great but most of time that is not case so we tend to find some cheaper solutions.

One of the reason today more and more people are getting in market with certifications is virtualization whether its emulating Cisco or Juniper router or running multiple OS(Microsoft, Linux) on single machine. And GNS3 is excellent tool to virtulize/emulate Cisco routers, but when I start learning Juniper I found it bit hard on how to emulate Junos as it runs on free BSD and me having no knowledge at all with linux find difficult to emulate but finally with help of our friend Google I am able to run Junos in GNS3 and build topologies to start with.

Now the question is how far I can go with Junos Olive without having physical router in my study plan. Well at this point I  really don't know :). I heard few things doesn't work in Jonus olive. So I did little bit research on getting physical routers. Or Even getting to that first look at what certifications does juniper offers.

http://www.juniper.net/us/en/training/certification/certification-tracks/

Above link shows Juniper offers three major tracks Routing and Switching Enterprise, Routing and Switching Service Provider and Security along with some technology specific tracks. In major tracks you start with Associate level (JNCIA) and go on all the way to expert level (JNCIE). And this is where you see whether you need to have physical lab what kind of exact products you need to add in your lab.  

This is just a short description on Juniper learning and possible options of hands-on labs.

I will be creating video on how to emulate Junos and making it work with GNS3. A lot is already available on internet you can do Google yourself my method may be the same like others but this will be my approach on running Junos olive.