Internetworking for system administrators

March 14, 2010 6:05 PM

I'm a senior-level Unix sysadmin and IT manager. I'd like to fill up one big gap in my experience but I'm not sure the best way to do it: large-scale networking.

I understand LANs, VPNs, switching, etc. and the basics of Internet routing, but I've never had hands-on time on something that speaks BGP, or learned IOS or JunOS, that kind of thing. But I'm in a small company, so it's not like I'll have some hands-on time on a Catalyst 6500, let alone carrier-level stuff.

Reading about the new Cisco CRS-3 got me thinking about that gap in my experience. Years ago I used to be able to find my way around looking-glass servers and oregonix's route-views service but I haven't had need to in a while.

I'm not interested in certifications, I don't think -- this isn't about finding other work, it's about rounding out my knowledge so I can see what's going on. What's a good approach to get up to speed on both the theory and practice of "advanced" networking?

posted by mendel to Computers & Internet (7 answers total)

There is some programs available that simulate the Cisco hardware, a quick look about gets me to the Cisco 7200 Simulator though you do need a copy of IOS to run upon it.

Alternatively, buy some lower-end hardware off ebay, play with it for a month or four then sell it back, you'll have some real experience on the physical product and it's limitations for not much (net) money.

From my experience, the Cisco certifications are well regarded as being "serious", they're not just rubber-stamps for money. So if you're learning the in's and out's and you just happen to have this certification at the end of it, then congratulations, because that's the win/win situation.
posted by Static Vagabond at 6:34 PM on March 14, 2010

You can build a JunOS simulator also (search for JunOS Olive); that may be helpful in familiarizing yourself with the JunOS environment.
posted by theclaw at 6:49 PM on March 14, 2010

Best answer: I come from an information security and risk management background and was recently put into a role where I am hands-on with core networking infrastructure (6500s and such). I had never been in networking before, and only had the conceptual level stuff that you would expect from someone working in security. Pretty good with layers, but no good with technical R&S stuff, and a total klutz in the data center. My knowledge of the IOS command line was non-existent.

I found the book Network Warrior from O'reilly to be absolutely huge to help start filling the gaps in my knowledge on R&S. It's more generic and conceptual and not vendor-specific, but very in depth. The book is something that I refer to constantly.


I also am doing CCNA and will do CCNP later this year using Cisco's official materials. There are some quicker ways to pass the tests, but I wanted more to actually learn the material than get the cert stamp.

The Network Warrior book and some IOS cheat sheets went a very long way though.
posted by robokevin at 7:20 PM on March 14, 2010 [1 favorite]

Here's a nice list of Cisco simulators or if you want a more structured environment to learn in you could go with something along the lines of NetworkSims self-study courseware.
posted by scalefree at 7:39 PM on March 14, 2010

Mikrotik hardware can be had for cheap, and their level 4 license has full BGP functionality. A simulator is a good start, too.

My company uses about 8 Mikrotik routers to maintain BGP tables between network locations. Their documentation is shamefully lacking in basics, but their tutorials on setting up and testing complicated networks is pretty solid. The RouterOS command structure is very similar to Cisco IOS as well.

Their RG750 router starts at around $40.

Alternatively, you could build a crappy x86 box with several NICs and just install RouterOS on it and see what happens.
posted by tmt at 9:32 PM on March 14, 2010

2nd Static and RoboKevin. Network warrior is a pretty great book and if you haven't you should check it out.
posted by anti social order at 8:02 AM on March 15, 2010

Response by poster: All very helpful! The Network Warrior book is pretty much exactly what I need to start out with, and then I can start using it as I find spare time with simulators.

For those coming in later, though, I'll add: while robokevin describes it as "conceptual and not vendor-specific", I'd say it's "conceptual, and additionally Cisco-specific" in that not only does it teach you the general concepts, it then tells you the IOS and CatOS commands to implement the concepts (which makes it even better than conceptual alone!).
posted by mendel at 4:13 PM on April 26, 2010