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June 2011

Cool, free tool-of-the-week: WinMTR

Thanks to Etienne who emailed me this fun Windows port of a Linux tool allowing you to perform a continual traceroute (thus, identifying the 'slow spots' in your network).


Cisco 4500 In Service Software Upgrade (ISSU)

Came across a nifty video featuring Jimmy Ray Purser demonstrating the Cisco 4500 Sup 7E and the new single line In Service Software Upgrade (ISSU) feature. 

If you are unfamiliar with ISSU, it basically lets you upgrade a router or switch to new code without taking a significant outage to reboot.  In the 4500 Sup 7E, Jimmy mentions a 10 millisecond outage during the upgrade - much better than several minutes. 

The video is embedded below. If you don't have flash, the link to it on YouTube is also below.



Epic Blue Screen of Death


Don't you just hate it when your 16 screen display stops working due to a Windows problem? It gives you that not so fresh feeling.

I'm sure the IT staff at DFW Airport felt that way yesterday when this awesome set of screens was proudly displaying Microsoft's OS at its finest moment. Credit for the photo goes to a road-warrior buddy of mine, Brendan. Thanks for sharing the love.

Cisco Security Advisories - AnyConnect Client and 7900 Series Phones

Cisco release a couple severe security advisories last week that are worth taking a look at if you use either the Cisco AnyConnect Secure Mobility Client software or Cisco 7900 Series IP Phones. I'll try to break them down in english below to help you see if you are vulnerable.

Sizing Your UPS: Watts and Volt-Amps

Great, concise article from APC explaining the difference between Watts and Volt-Amps...key when sizing a UPS for your Cisco gear.


If you have been thinking about going for the CCNP certification or are already working toward that goal, you have undoubtedly wondered what the TSHOOT exam has in store for you. Jeremy posted his thoughts on it after taking the exam last year. The official Cisco TSHOOT page also has specific information about the exam. However, sometimes it helps when the information is spoon fed to you in a video format. 

I stumbled on the following video and figured it was worth sharing. Not only was it informative, it reminded me of the pre-flight "fasten seatbelt" routine flight attendants go through when you travel. 

Macs are no longer immune

If you are a Mac user, you most likely have heard about MacDefender (AKA, a pile of garbage). For years, Macs have been immune to attacks due to their low market penetration and small user community. In the past, from a virus writer's perspective, why aim at elementary school libraries and a handful of eclectic technologists when you can get credit card numbers and bank accounts from the millions of Windows users around the world. Well, those pleasantville days are over as 
Apple outpaces the PC market
with double digit growth. 

Pop Quiz - Subnetting Challenge

Here are some subnetting questions to get the synapses firing on a Friday:

1. What range of addresses are encompassed by the summary address





2. You need to configure a new branch office LAN with at least 812 usable IP addresses. The site desktop manager wants a single range of addresses to make it easier to configure the gateway and subnet mask on the computers and printers being deployed. Your company uses the address space for internal networks and the subnet has been reserved for new branch office LANs (WAN links are in a different subnet). Starting with the first available network in the reserved range, what is the most efficient subnet and CIDR mask for this new branch office?





3. The following access list is filtering traffic:

access-list 1 deny

access-list 1 permit any

Which of the following addresses will not be dropped? (select all that apply)





Answers after the break:

Nice CME Configuration Example

Found this while surfing the Internet; great configuration! Keeping here for easy finding.

Begin CME Configuration:

Microsoft Power Point - Wrap Text Around An Object

If you use Microsoft Power Point on a regular basis, you may have already figured out that unlike the other Office products, Power Point is lacking a useful feature. Text doesn't automatically wrap around a picture when you drop it in the middle of a block of text!

I have used the Office suite for over a decade (and have even taught people how to use it), but I don't recall ever trying to drop a picture into a block of text and have it wrap around in Power Point. It works in Word, but not here. When I first had this happen, I figured there must be some obscure check box buried deep within the options and preferences that would enable text wrapping. After a bit of searching, no such check box was found. 

Well, after some research, I discovered somewhat of a public service announcement on Microsoft's site explaining how to do this manually since the feature was left out of Power Point 2010. At least they remembered to write a how to... 

VirtualBox: Free Virtualization for OS X / Windows

Why do we purchase Apple laptops? So we can have a cool looking laptop where we can run Windows in a virtual machine to do anything useful! ...I'm kidding...sort of...

I've spent close to 200 bucks over the years for various versions of Parallels/Fusion software...and then Oracle decides to release free virtualization for OS X / Windows that performs better than both Parallels & Fusion.

Here ya go:

Firefox 5 - Rapid Fire Release

Feels like it was just a few months ago we were installing the brand new Firefox 4 and now it is obsolete! That's right, Mozilla is laughing at Murphy's Law and coming out with a major rev of their software every 3 months instead of their previous schedule that was much more sane.

According to, "Mozilla Firefox is moving to a rapid release development cycle to
deliver new features, performance enhancements, security updates and
stability improvements to users faster."

So, if we're understanding this correctly, they want to deliver updates to their users like they always have, but they want to throw the whole concept of subversions out the window and stick with major releases. As a regular end user, I guess I can roll with that.

Proof that REAL Cisco techs use Firefox

Monthly browser report from (the browsers ya'll are using when you visit)

Firefox 43.63%
Internet Explorer  25.21%
Chrome  20.24%
Safari  7.59%
Opera  2.00%

What's up with the 2% opera? What draws you to that browser?

Tekcert Forums Are Here

After months in the works, the Tekcert Forums are officially open to the public! 

For the next month or so, the forums will be in "beta" - this is to ensure things are running smoothly enough to let the forums continue to run. During this period, I will be making modifications and improvements to the forums. Also, I hope that you, the readers, will step up to the plate and become contributors as well. Create an account, login, and post to the forums.  Let me know if you run into any problems or tell me if you have a suggestion to improve the forums. To send me feedback, use the Contact form located here.

I've put in more hours than I care to admit on implementing a forum system that is "integrated".   I looked at various options of implementing a separate open source forum system such as phpbb, but it made more sense to allow people to login once and post on the forums or comment on the blogs with the same account. So, if you create an account and login, you will be able to post to the forums as well as comment on blog posts without having to type in your name or be labeled "anonymous". Please be aware that you should read and agree with the Terms and Conditions of the site AND you will need to follow the Commenting and Forum Thread Guidelines

I hope this becomes a useful source of information for everyone. I've tried to create more certification focused forums, but if you want some new forum categories let me know and it might get added. 

Thanks and Happy Posting!


I hope this will be informative for us! :)

IPv6 Tunnel

Ok i'll throw the first question up !!!
I've setup IPv6 connectivity using an IPv6 Tunnel Broker (a bit before IPv6 day).
Unfortunately i have a Dynamic IPv4 public address through my ISP, so when this IP changes i loose IPv6 Internet because my end of the tunnels IP address has changed.
Now the tunnel doesn't actually go down at my end (up/up), as my endpoint has not changed, just the tunnel brokers endpoint has changed ? (my IP).
To get full IPv6 connectivity back up, i have to log into the tunnel broker and manually change my Public IP, i have no problem doing this, it's just detecting that it's required.
I'm running a syslog server, i was hoping there is a way to configure the router to detect and log that there is no longer 2way connectivity to the IPv6 internet.
One way is to setup an SLA to ping an IPv6 address like ipv6google ?
Open to suggestions ? ?

Studying for CCNP Route

Having passed my CCNA last year I now want to attempt CCNP ROUTE. I am not working on routers day to day now so I will have to do most of the work in a lab. Just wondering how long others have taken to study and also which methods they find best.


Setting up lab to home network

I'm currently studying for the NP Switch exam and I'd like my switches to reach the internet. My idea is to NAT the traffic through my PIX 515e to create a route back to the lab equipment. I'm using the pix because its the only device I own capable of NAT. However the pix isn't allowing any traffic through it. I'm frankly tired of spending valuable study time goofing with a device unrelated to my studies. And internet access isn't necessary now anyway. My question is, how are you guys connecting lab equipment to your home production network?
THanks in advance