Monthly Archives: November 2015

Cisco VIRL – 20 Node IOSv Test

Greetings!! So I’ve been playing with the latest Cisco VIRL release (v1.0.0), and let me say for the record, I like it!! Of course I’m still relatively new at VIRL and have much to learn, but I am very impressed by the latest release. AND I’m very pleased with the new bare-metal VIRL installation I have!

If you recall, several months ago, I installed VIRL on my new desktop system (Quad core i7 processor, 32 GB of RAM, fast SSD and storage drives, Windows 8.1 and VMware Workstation 11). VIRL ran very well on that system, which is to be expected, but there were times when my PC just behaved a bit strangely…a bit of pausing, some hiccups…you know what I mean. Of course I was running other power hungry programs at the same time…Photoshop and Lightroom. This installation is a bit more complex…you have a physical PC, running Windows 8.1 for an operating system, running VMware 11, which runs a VM (Virtual Machine), which is running Linux, which then runs it’s own VM that runs the network simulation (routers, switches, etc). Whew…it’s complicated just typing all of that out!

So…I decided to upgrade my Dell 2950 PowerEdge server a bit. I added RAM and another processor, so it now has: dual Quad-core Zeon processors (3 Ghz); 16 GB RAM; and fast 15K RPM drives. Let me tell you…this thing screams. Yes, it has less RAM than my PC, but now it will be dedicated to just Linux and the network simulation…nothing else. The new setup is much simpler now…a physical server, running Linux, which runs a VM for the network simulation.

How does it work? NICE!! I setup a test 20 node router simulation and cranked it up…it took about 2.5 minutes for all nodes to go ACTIVE, and another 1.5 minutes for BGP and OSPF convergence to complete. Here’s the topology for the test…

20 Node VIRL Simulation

And here are the resources used…

Resources used for 20 node test

Everything is looking very good here. Of course, I am using just IOSv nodes (routers)…they are the least CPU and RAM intensive. If I were using other node types (NX-OSv, ASAv, CSR1000v, etc) then I would be running out of resources sooner and would have to balance the number and type of nodes I could run in a simulation. What will help is to upgrade my RAM to 32 GB, which I will do early next year.

Do you like what you see? Then take a look at VIRL…I think you will be very pleased.

Run the Race – Living a Life of Generosity

In this world of always wanting more (especially here in America), I found this article to be an inspiration to my soul…

Alan Barnhart Limits His Salary

It seems that no matter how much you make, you always need a bit more. And a lot of us Christians are in the same boat as the general public. Just think what our impact on the world around us could be if we lived within our means, and used the surplus to bless those in need…the impact would be earth shattering!

Not sure where to start? Take a look at the materials available from Dave Ramsey…it’s a good starting point if you really want to live within your means and to use your finances wisely.

Cisco VIRL – New Feature Release v1.0.0

Cisco just released yesterday (November 26) an updated version of VIRL (Virtual Internet Routing Lab), version 1.0.0….and let me tell you, it has some great enhancements! You now have the ability to modify parameters on a link…you can configure latency, packet loss and jitter. AND they have increased the node count to 20 (up from 15). This is WAY cool stuff! First though, you need to upgrade to the new version, which I just did.

NOTE: This post is just a high-level overview of a VIRL installation, so you can get a taste of what it takes to install it. Please reference the noted links below to get the full instructions when you are ready to install VIRL. A great place to start is the Cisco VIRL homepage.

STEP ONE: Download the new VIRL version. Normally you have to wait for an email which has the download links and grab the image within 3 days (after which the links expires). But Cisco has finally setup a “self-service” download process which allows current VIRL users to download updated images whenever you want. (See this Cisco VIRL announcement for lots more details.) From your current running VIRL install, you can open up a terminal window to grab the new image…since I’m running VIRL on a bare-metal installation, the commands were…

Self-service download of new VIRL image

STEP TWO: Installation. Unfortunately, you cannot do an in-place upgrade…you must do a fresh install. Go to the VIRL installation documentation and pick your method (for me, it’s ISO to Bare-Metal), and follow the directions. It will take time, so be patient and follow each step carefully.

STEP THREE: Troubleshoot issues. Hopefully your installation will just work. However, in my case, I had an issue…the “linux-bridge-agent” was not up and running…

Bare metal issue: linux-bridge-agent not running (no smiley face!)

It took a lot of time to figure this one out, but I found a posting that addressed this issue. It has to do with running VIRL on a bare-metal server that does not have the minimum required 5 physical interfaces. You can setup dummy interfaces to handle this, which I had done, but there were some additional steps needed to fix some bugs…here is the link if you have the same issue.

So, now things are working properly…

All four agents are running!

And all services are running!

Time to install the license key and make contact with Cisco’s salt servers…

Successful contact with SALT servers

At this time, the VIRL installation is up and running properly. Now it’s time to install the frontend to VIRL, called VM Maestro, so you can create and run network simulations. Just follow the instructions, and this is a very quick step. When logging into VM Maestro for the first time, make sure and enter the IP address as well as the password…only then will the client make the proper connections and the web services go “green”…

With the proper server IP, username and password…everything goes green!

Now that everything is up and running, I configured a simple 4 node router simulation…and added 100 ms of latency between node San Francisco and Los Angeles, like so…

Adding latency to a link

Before I failed any of the links, the ping results from San Francisco to New York were…

Normal latency between San Francisco and Los Angels

After I failed a couple of links, which forced the traffic through Los Angeles to reach New York, ping results showed the higher latency…

Ping results with high latency

This is VERY cool…and there is much more to this new version…I have only just touched the surface of all the new features. Cisco has done a great job of putting a fully functional network simulator into our hands….let’s make great use of it, and let’s give Cisco our thanks!! They deserve it!!

New Versions of NMAP and Wireshark

If you have not already heard, new versions of NMAP and Wireshark have been released recently. These are my favorite open source programs, and to be honest, pretty much my favorite programs period. They are both maintained and managed by a dedicated team of people, and the quality of the software shows. Plus, the main authors (Gerald Combs for Wireshark, and Fyodor for NMAP) are both class acts…

NMAP is THE tool for running forensics on your network…to find the weaknesses before the bad guys do. It has MANY parts, which all work together in a very seamless manner, and should be in every network engineers tool kit. If you are not using it, stop what you are doing and get it now!! (Enough said!!) New version is 7.00.

Same thing about Wireshark. I’ve said it before and I’ll say it again…if you don’t have a network analyzer, then you’re not really a full and complete network engineer. Get it and learn it. There are plenty of resources on the Internet, for free, to help you get started (Google is your friend), and if you want to pay a little bit of money, Laura Chappell has a great website devoted to Wireshark training.

I just downloaded the updated Wireshark today (version 2.0.0), and I have to say the default screen is spartan, to say the least. Not sure if this is temporary in this initial v2 build, but either way, it does not look like it’s predessor. Note how clean (and empty) the startup screen is…

Initial Wireshark startup screen

Here is some info from Gerald about this new version. I’m looking forward to learning what it has to offer!

Riverbed Interface Configuration via Command Line Interface (CLI)

Yes, it’s been a while since I did much of any postings, but I’ve been both very busy at work and out of state on vacation. Things are starting to calm down a bit now, so back to some network related postings…

I worked late last night upgrading a batch of out-dated Cisco 3750 switches (first generation), installing a stack of new 3650 switches. I have to admit, these switches are nice! But like most all of Cisco’s stuff, they don’t play well with other vendors products in terms of interface auto-negotiation. The existing switches were all 10/100 interfaces, and we had a Riverbed device installed between the switches and router, so all of the related interfaces were manually configured for 100 Mb, full duplex.

Since the new switches were all gig, and the router was too, I reconfigured them for auto/auto for both speed and duplex. But I needed to configured the Riverbed device too. (When I first brought everything online, the Cisco devices came up 100/half….not good at all.)

Since the GUI interface on the Riverbed does not handle interface configurations very well, I connected to the device via SSH and configured the interfaces using the command line…which as we all know is the best way to do anything!! As you can see, interface wan0_0 is configured for 100/full…

Command showing current settings for wan0_0 interface

To change the configuration is easy…here are some of the options…

Interface configuration options

And here I changed both wan0_0 and lan0_0 interfaces for auto/auto operation…

Setting interfaces to auto/auto

It was that simple. I then unplugged both cables to my router and switch, reconnected them, and all interfaces came up 1000Mb (gig) and full duplex.

Working with Riverbed on the command line is rather easy, and you will find many of the commands are similar to Cisco.

Beautiful Visit to Upstate New York

Sorry for the lack of posts lately…been too busy at work, and now my wife and I are in upstate New York visiting my daughter and her family….AND getting some good bonding time with my new granddaughter Evelyn. She is just way too cute….

Holding my new granddaughter!!

I’ll get back to my postings in another week or so, once I get back from vacation.

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