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Book Review: MPLS Fundamentals from Cisco Press

If you are in the market for a good MPLS resource, check out the Cisco Press book MPLS Fundamentals: A Comprehensive Introduction to MPLS Theory and Practice. I've nearly finished reading this over the past few weeks and it's definitely a great place to start if you have never really worked with MPLS.

Of course, everyone is still waiting for an MPLS CBT Nugget from Jeremy.  However, until something like that is created - if you need to know more about the technology this is a great resource.

TwitterChat this Morning - 9am PST

Update: Thanks to everyone who participated!
View the Transcript here...

My first Cisco Live 2012 is this morning (5/10/12) at 9am PST: TwitterChat!

Feel free to join #CLUS and hang between 9am - 10am. CBTNuggets will be continuing the fun from 10am - 11am at #CBTchat.

See you soon!


Care to TwitterChat?

Well, it appears my friend Adam beat me to the punch on the Cisco Live posting. So, here's my additions from a personal side.

  1. Cisco has scheduled me for a TwitterChat next week on Thursday- please come and jump in! This was surprisingly fun when we did it last year. Here's the information:
  2. For those coming to Cisco Live 2012, I'll be presenting a wonderfully amazing and dazzling session (watch me pull a rabbit out of my hat!) on CCNA Voice. The session is scheduled for 12:30pm on Tuesday - if this is even half as fun as it was last year, it will be a blast!
  3. I'll also be doing a Cisco Press "Meet the Author" session at Cisco Live 2012 at 4:30pm on Tuesday  in the Cisco Press booth.
See you soon!

Cisco Live 365

Cisco has created a new rendition of their Cisco Live website called Cisco Live 365. You can register with the site for free and gain access to some of the conference materials presented at the various Cisco Live conferences around the world throughout the year.

If you are signed up for (because you are attending Cisco Live in San Diego this June), then your credentials for that website don't apparently work automatically at the new site. To get access to the new site using your current credentials, login to the old site, then click on Registration, and click on the huge button that says Enter Cisco Live 365. A new tab or window should open and voilà, you're in.

How to concatenate multiple text files into one

Command Line

Have you ever wanted to merge a bunch of text files together into one large one? For example, if you use a tool to go grab a bunch of show command results and output it to a text file per device, it's handy if you can have the operating system merge all that together for you. Many of you have likely done this at one point or another, but I figured it was worth capturing here to share the syntax.

So, if you are in a Windows command prompt, you can use the type command to output the contents of a file.

C:\>type text1.txt
This is a test. 

Then you can use the type command plus the double arrows to merge a bunch of files:

C:\>type *.txt >> merge.txt





This leaves you with all the original files plus a new one called merge.txt. Piece of cake.

GNS3: Save a little memory with VPSC

This tip was emailed to me and seems pretty sweet (haven't tested it). Check out this link:

Rather than eating up resources using routers as hosts in GNS3, you can use a Virtual PC Simulator (VPSC) that can ping, traceroute, get a DHCP address, etc... 

While this is good in theory, I'm curious how difficult it is to roll this into the Windows version. With memory becoming a cheap commodity, it's just too easy to drag another router on the GNS3 landscape.

CBTNuggets Update: BGP Ready...What's Next?

Hello all!

Over the last week, I put the finishing touches on the Cisco BGP Series over at CBTNuggets - that's definitely a fun one! Now I'm charting out...what's next? The logical answer is MPLS (a sister series to BGP), but the rumors say that the MPLS certification will soon be discontinued and replaced with alternative Service Provider offerings.

So here's my grass-roots poll: What Cisco certification training should come next at CBTNuggets?

I've recently been breaking out of the "certification mold" with offerings like CCNA Labs: Cisco for the Real World ( If there's an idea like this that you might have, I'm all ears!

Upgrading 3750X can take longer than you think

I recently upgraded a Cisco 3750X stack to a newer version of IOS. Since the production system I was planning to upgrade had some critical systems on it, I tested the process on a stack in the lab first.

At the outset I figured "no problem, this will take a few minutes to reboot and we'll be back up and running." Little did I know I was in for a long wait... Unbeknownst to me the version of code I was upgrading to included a Microcode update which adds a considerable amount of time to the process... emphasis on considerable.

The stack was running 12.2-53.SE2 and I was upgrading it to 12.2-58.SE2, which at the time of the upgrade was the recommended 12 version (I've had problems with IOS 15 on this platform, so I'll be sticking with version 12 for now).

Networking 101 Video - Switch Latency

Jimmy Ray Purser from TechWise TV  provides a pretty good review of how switch performance is measured. Topics reviewed include cut-through switch latency, store and forward switch latency, FIFO, LIFO, and LILO. Check it out if you've always wanted to know how to measure the speed of a switch.

Here's a direct link if the video embed code doesn't load in your browser:

Forced Memory Upgrade on a Cisco ASA 5505

ASA 5505

About a week ago, my home Internet connection started to show signs of degradation. Emails weren't being sent, websites partially loaded, and in general things were "slow". If this was an enterprise network and I was a non-technical user, I would have promptly opened a help desk ticket with the title of "the Internet is Down!" or "The network is slooow". Since this isn't exactly an enterprise network (cobbled together hodge-podge is a more accurate description) I knew it was up to me to make things right. So, I quickly put on my troubleshooting hat and went to work.

After a bit of looking (and reboots), I found a solid amber status light on my ASA5505. This was the last place I looked because the thing has been as solid as a brick for the past 4 years. I tried to connect to it via SSH and Console, neither worked. Rebooting it did nothing. 

Wireshark updated to version 1.6.6

A new version of wireshark has been released. A full list of features and updates are in the official announcement.

For reference here is the updated protocol support and new file capture support:

Updated Protocol Support

   PacketBB, PGM, Radiotap, SSL, TCP, UDP, USB, WSP

  New and Updated Capture File Support

   Endace ERF, Pcap-NG, Tektronix K12

You can download the latest version here:

Cisco Acquires Lightwire


Cisco announced yesterday their acquisition of Lightwire, Inc., a company that manufactures network transceivers. Since Cisco already offers their own brand of optical transceivers, this deal will most likely give them a cost cutting edge for creating high speed optics.

According to the press release, the deal cost a cool $271 million. 

The intellectual property and manufacturing processes gained in this deal will likely help Cisco make better optics. However, the retail price points will likely remain unchanged, so Cisco should expect to see higher margins on future high speed optical sales. If you've ever bought a fully loaded Nexus 7010, the optics are a significant percentage of the price.

CCNA Service Provider

I received an email announcement today regarding Cisco's new CCNA Service Provider certification. This is in addition to the already available CCNA Service Provider Ops certification.

There are two exams that need to be passed in order to achieve this certification, the SPNGN1 and SPNGN2.There are no prerequisites.

You can check out the full list of exam topics on each exam page, but needless to say the list is extensive. By the end of the certification, you should have a good introductory understanding of the following:

Cisco Security Advisory - NX-OS Denial of Service Vulnerability

Cisco recently announced a vulnerability in their NX-OS for the 1000v, 5000, and 7000 platforms. If you are running Nexus in your network, be sure to check this one out because it could cause an outage.

In order for this vulnerability to be exploited (or randomly occur), a malformed IP packet has to enter into the Nexus and one of several conditions can trigger the problem. The advisory notes provide a few examples of how to trigger the problem including the following: a malformed packet with a TTL value of 1 that would cause the Nexus to send an ICMP time exceeded error message. The process of generating the ICMP message could trigger the bug.

What's Vulnerable and How do I fix it?

Here's a list of the versions with the vulnerability and the version with the fix, per platform:

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by Dr. Radut