Building a Juniper olive lab and playing with it is no different than gathering Cisco OS images and stuffing them into GNS3 or eve-ng. This articles describes some of my ramblings.

As you know, in order to play with Juniper Junos in a lab, you need to configure instances of Olive. In my home lab, I have configured 6 Juniper Olives to play with. This is an overkill for JNCIA and JNCIS. But I got hooked on this topic for a couple of days. I remember waking up and labbing at 4.20 am building Olives LOL. Maybe my motivation behind that is that I wanted to practice every Junos topic on the exam guide as quickly as possible.
So here’s the topology of my first Juniper home lab:
juniper olive home lab

Candidate Configuration vs Active configuration in Junos

Let’s check show configuration interfaces on the operational mode:

show configuration interfaces on juniper olive

We have the same output with “show interfaces” under [edit interfaces] level:

show configuration interfaces under edit mode on juniper olive

Let’s make a little change under interface tap (I added a description ):

added description under the interfaces

Now, if we issue a “show configuration interfaces” again, we’ll have a different output than with “show interfaces”:

It’s because the active configuration and the candidate configuration aren’t the same here. How do we view the difference? “show interfaces | compare rollback 0” which compares the interfaces section between the active and the candidate configurations:

Making Juniper Olive instances talk together

I spent a few hours on this issue. And after consulting with a friend, I figured out that I need TAP interfaces, Bridging and fxp logical interfaces.
So If I want to have 6 Juniper Olives connected in some kind of network, I should have 6 bridged TAP interfaces. The remaining work is to create units under interface fxp0, each unit tagged with a seperate vlan-id.
What if I have Router A connected to Router B and Router C? Router A would have 2 connections. So does it need 2 TAPs?
No. Only one TAP. See TAP interfaces as “pipes”. When bridged, it means routers can communicate. period.

Himawan Nugroho details this issue in one of his blog posts.

Basic ATM Interface Configuration On Juniper JUNOS

juniper junos atm error message

I thought ATM interfaces are configured just like any other juniper interface. How stupid I was, LOL. I got this error message on the right.

So JUNOS needs us to specify the ATM PIC type and the VPI/VCI number.

Configuring the ATM PIC Type #set atm-options pic-type atm2
Configuring the VPI #set atm-options vpi 0
Configuring the VCI #set unit 100 vci 100
Configuring the IP address #set unit 100 family inet address 10.0.16.2/24

I chose the VCI number identical to the unit number; it’s just a best-practice. And don’t forget to commit your configuration!

Here is what it would look like:

junos atm interface configuration

BGP Traceroute options

#set protocols bgp traceoptions file bgp
#set protocols bgp traceptions flag update detail
#set protocols bgp traceptions flag keepalive detail
#set protocols bgp traceptions flag open detail
junos clear bgp neighbor

Now in normal operation, we should only see keepalives:

Then I issued a clear bgp neighbor and that led to sending Notification messages:

Then we receive the OPEN messages:

Categories: Juniper

Keyboard Banger

Keyboard Banger is a network engineer from Africa. He has been working in network support and administration since 2008. He started writing study notes about certification exams and technology topics a couple of years ago. When he's not writing articles, he can be found wandering on technical forums.

1 Comment

Cisco Catalyst 3650 Switches Overview | A Network Engineer's Blog · March 21, 2020 at 11:10 pm

[…] from Cisco. Yes, these are Catalyst 3650 switches, which look elegant and remind me of the old Juniper EX4200 switches. They have 48 PoE Ethernet Gigabit interfaces and four 1G SFP ports for […]

Leave a Reply

Your email address will not be published. Required fields are marked *