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JUNOS First Impressions
I’ve decided to jump head-first into JUNOS. My short(ish) term goal is to find a position with a service provider. I’ve read that Juniper owns a very significant portion of the SP core, so any exposure to JUNOS can only be a good thing (or so I hope). JUNOS is (obviously) very different from IOS. This is mainly about my experience as an IOS guy starting out with JUNOS.
Likes
- JUNOS is modular, which means more process separation and stability.
- JUNOS has less versions (no ipbase, advanced enterprise, etc.
- Commit feature – This allows you to input multiple commands before making them active.
- Rollback feature – JUNOS saves the last 50 committed configs, allowing you to revert to an old config.
- Command completion is a little better in JUNOS, you can use spacebar or tab. It will also pick up things that IOS wouldn’t, like user-set variables in the config.
- The ability to use CIDR notation in JUNOS, this is very, very nice.
- JUNOS has better pipe functionality than IOS with show commands
Dislikes
- It’s not IOS
- Simple things (NAT, static routing, IGP, BGP, etc) can become very complex due to the hierarchical nature of JUNOS.
- Show command outputs. It’s harder for me to find information in some of the outputs. This one doesn’t count really as it’s mainly because I’m so used to IOS
So far, I don’t hate JUNOS, which surprises me a little. Once you get the basics worked out it’s not so bad and JUNOS definitely has some features I wish the traditional IOS had. I don’t see myself becoming a total Juniper zombie yet, but I will definitely keep playing with it. I plan on making a post or two about the simple stuff like basic setup and OSPF configuration.
Related Posts:
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Who’s A JNCIA-ER?
about 2 years ago - 12 comments
I am!
Last week I decided to put the CCIE on hold for awhile due to the new troubleshooting section. I feel like I could use another year or so of experience under my belt before trying to tackle that monster. I’ve been meaning to sit the CCDA exam for a few weeks now, but haven’t really gotten motivated enough to do it. Then I started tinkering with Juniper…
I went through the Fast Track stuff and did the pre-assessment last Sunday to get the 50% off. Oh a whim, I decided to do some studying and see how bad the test is, with the 50% off it’s only ~$60, so it wouldn’t upset me too bad if I failed.
I didn’t fail. The test was really, really easy, not to discount anyone who has taken it or anything, but it’s very basic. It had more advanced topics than the CCNA, but not much depth. I don’t want to break the NDA, but basically you just need some familiarity with the different Juniper models, some experience with the JUNOS CLI and J-Web (more J-Web than I’d have preferred – I used this guide from Juniper to learn it). You also need to know basic OSPF and VRRP concepts, and routing concepts in general. All in all, it’s really not bad, I think someone with a CCNA and some Juniper experience should be able to study for a week or so and knock it out with no problems.
Not sure what’s next. I really want to get the CCDP soon, so that means the DA should be my next priority. I’m definitely not done with Juniper certs though. I’d like to go for the JNCIS in the new few months. The pre-assessment for that one is much more difficult than the IA, so I imagine I won’t be able to breeze through the real exam.
Related Posts:
Basic JUNOS Configuration
about 2 years ago - 8 comments
Today we’ll go over a very basic JUNOS configuration, we will configure the hostname, user account, IP addresses and a default route. The purpose of this article is to provide a look and feel for JUNOS.
First let’s login and take care of the basics:
root> configure [edit] root# set system host-name Olive1 [edit] root# set system login user colby class super-user authentication plain-text-password New password: Retype new password: [edit] root# commit and-quit commit complete Exiting configuration mode |
This is a simple config, we enter configuration mode, we set the hostname of the router then we configure a user named “colby” in the “super-user” class. “Super-user” is a pre-defined class in JUNOS, this class has full control of the router.
Anyone familiar with IOS can see that this is pretty different. The commands all start with “set” and they can be quite a bit longer. Let’s take a look at the hierarchical view of what we just did:
system {
host-name Olive1;
login {
user colby {
uid 2000;
class super-user;
authentication {
encrypted-password "$1$IKhmMCbo$XNAWMDS"; ## SECRET-DATA
}
}
}
} |
Definitely not what I’m used to, but not so bad. Now we’ll configure the same thing with multiple commands from the hierarchy:
[edit] colby@Olive1# edit system [edit system] colby@Olive1# set host-name Olive1 [edit system] colby@Olive1# edit login [edit system login] colby@Olive1# set user colby class super-user authentication plain-text-password New password: Retype new password: |
I prefer to stay at the top of the hierarchy and use as few commands as possible, but it seems that many people like digging into the hierarchy. The rest of the configuration in this article will be from the top using as few commands as possible.
Next we’ll do a “show interfaces terse”, which is like our old pal “sh ip interface brief” in IOS:
colby> show interfaces terse Interface Admin Link Proto Local Remote dsc up up em0 up up em1 up up gre up up ipip up up lo0 up up lo0.16384 up up inet 127.0.0.1 --> 0/0 lo0.16385 up up inet lsi up up mtun up up pimd up up pime up up tap up up |
This looks a little different than “sh ip int b”, but it’s very easy to read. The interfaces we’ll be working with today are “em0″ and “lo0″, em0 is our ethernet interface (this is how they’re named in Olives running in VMs apparently), and lo0 is our loopback.
Let’s give em0 an IP address:
[edit] colby@Olive1# set interfaces em0 unit 0 family inet address 192.168.25.100/24 [edit] colby@Olive1#commit commit complete [edit] colby@Olive1# run show interfaces terse Interface Admin Link Proto Local Remote ... em0 up up em0.0 up up inet 192.168.25.100/24 ... lo0 up up |
We’ve set an interface on em0. The command configures a logical interface with an ipv4 address of 192.168.25.100/24 (255.255.255.0). We use “unit 0″ on this ethernet interface since it is not a tagged/trunk link. We have basically configured the equivalent to a subinterface in IOS, but this is normal practice for assigning IPs to interfaces in JUNOS.
Let’s give our loopback an IP too:
[edit] colby@Olive1# set interfaces lo0.1 family inet address 192.168.30.1/24 [edit] colby@Olive1# run show interfaces terse Interface Admin Link Proto Local Remote ... em0.0 up up inet 192.168.25.100/24 ... lo0.1 up up inet 192.168.30.1/24 |
The same as configuring a physical interface. Here’s a look at the hierarchy:
interfaces {
em0 {
unit 0 {
family inet {
address 192.168.25.100/24;
}
}
}
lo0 {
unit 1 {
family inet {
address 192.168.30.1/24;
}
}
}
} |
Now we need a default route so we can send and receive traffic:
[edit] colby@Olive1# set routing-options static route 0.0.0.0/0 next-hop 192.168.25.1 [edit] colby@Olive1# run show route terse inet.0: 5 destinations, 5 routes (5 active, 0 holddown, 0 hidden) + = Active Route, - = Last Active, * = Both A Destination P Prf Metric 1 Metric 2 Next hop AS path * 0.0.0.0/0 S 5 >192.168.25.1 * 192.168.25.0/24 D 0 >em0.0 * 192.168.25.100/32 L 0 Local * 192.168.30.0/24 D 0 >lo0.1 * 192.168.30.1/32 L 0 Local |
That’s our very basic JUNOS configuration. We’ve configured a user, given the router a hostname, and set up IPs and routing. Here’s our hierarchy at the end:
system {
host-name Olive1;
login {
user colby {
uid 2000;
class super-user;
authentication {
encrypted-password "$1$IKhmMCbo$XNAWMDS"; ## SECRET-DATA
}
}
}
}
interfaces {
em0 {
unit 0 {
family inet {
address 192.168.25.100/24;
}
}
}
lo0 {
unit 1 {
family inet {
address 192.168.30.1/24;
}
}
}
} |
For reference, this is the same config in IOS:
hostname Router ! username colby privilege 15 secret [password] ! interface fa0/0 ip address 192.168.25.100 255.255.255.0 ! interface lo1 ip address 192.168.30.1 255.255.255.0 ! ip route 0.0.0.0 0.0.0.0 192.168.25.1 |
IOS needs more commands typed out, but the JUNOS commands are much longer. In my next JUNOS post I’ll go over OSPF and maybe NAT, if I ever figure out how to make it work.
Related Posts:
JUNOS As A Second Language
about 2 years ago - 1 comment
So I’ve been realizing how lost I am in JUNOS and it bugs me. I’ve been going through the JSL course that a friend linked me to me awhile back. Juniper offers this course for free (very smart, IMO) and you can view it online or download it. Here’s a blurb from their site:
About This Course
For those of you who are familiar with Cisco's IOS, learning Juniper Networks JUNOS operating system is now made easy with JUNOS as a Second Language. Using an advanced graphical display, this course compares the similarities and the differences between both operating systems and shows the benefits of using JUNOS software. This 90-minute program is designed for network engineers who are already well-versed in Cisco's IOS software but who might not be as familiar with Juniper Networks JUNOS software.
Building on existing IOS configuration knowledge to provide a high-level overview of the JUNOS software, how it works, and how it compares with IOS, this course covers the following:
* JUNOS Software Fundamentals
* The CLI
* Configuration Fundamentals
* Interface Configuration
* Ethernet Interfaces
* Serial Interfaces
* Interface Monitoring
* Firewall Filters
* Routing Protocol Fundamentals
* OSPF
* BGP
Upon completing this program, users who were new to the JUNOS software will now have a good familiarity with it and be a step closer to qualifying to attain the JNCIA-ER certification.
It’s a very good course, especially considering that it’s free. Here’s the link:
about 2 years ago
I really like the commit and rollback features, and am surprised Cisco hasn’t ripped it off in some way or another yet.
Check out ‘JUNOS as a second language’ which should still be free from Juniper (might have to sign up for something). Does a good job of relating it to IOS.
about 2 years ago
I’ve been wondering what JUNOS as well myself, so I’m quite looking forward to your next bunch of posts on this one Colby!
about 2 years ago
@Rob: I wish Cisco would rip them off, lol. I’d love to have those features in IOS. I went through JSL pretty thoroughly yesterday, it was helpful (I even have a blog post about it
).
@Jared: I’m glad there’s some interest in JUNOS posts. I’ll add that to the top of the list, hopefully I can throw something together in the next few days.
about 2 years ago
Once you get past the Hierarchy of Junos it’s really pretty simple. Working with the J2350 has been a challenge, but has been a learning experience. It is not IOS by any stretch of the imaginations.
The biggest thing that I like and I know you say you hate it, but I like how you can do most of the commands in 1 line.
I’m waiting to see blog posts about this too
about 2 years ago
You say it’s pretty simple, but you didn’t know how to do any of the advanced stuff I asked you.:-P
You can do some of the commands in one line, but a lot of them need multiple lines, like adding user accounts, and route policies, etc. I’m still learning though, maybe it will continue to grow on me.
about 2 years ago
Just checking out your blog from your link on EE
Did you know that GNS3 now supports JUNOS though the QEMU package!! I am very excited about that. I have wanted to jump into the JUNOS world for a while just have not had the hardware. I have read about beans (or VM images of JUNOS) but have not had the time to dig into them.
Look forward to your adventures.
That1guy15
about 2 years ago
Man, once you know JunOS, you’ll wonder where it’s been all your life!
Some show commands give you far more info than IOS will. ‘show route extensive’ for example tells you exactly why a route wasn’t installed into fib.
You have an Olive setup yet? Very handy, especially connecting to Ciscos via dynagen/gns
about 2 years ago
@that1guy: Yea, I’ve read that the new GNS3 supports Olives (is that what you mean by beans?). Definitely jump into JUNOS whenever you get time, it’s fun to see how other vendors do things.
@Jason: Everyone keeps telling me they like it better than IOS, but I can’t imagine why.:-P I have two Olives setup on my ESX box, and a J2300 in transit to my house. My post today is about my experiences playing with the Olives.
about 2 years ago
@Colby: sorry I meant Olives. My mind was somewhere else yesterday
about 2 years ago
Haha, yea, I hear ya.
I thought it was something cool I’d never heard of, you had me all excited.
about 1 year ago
IOS has a rollback feature called archive. You can find documentation on Cisco’s website.
about 1 year ago
True. Cisco has caught up a bit, but it still isn’t supported natively and not too many people out there know of the Archive feature.