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Tekcert is back!

Thank you for your patience during the recent extended hiatus. There were issues with the previous hosting provider and migrating the site proved to be a greater challenge than first anticipated.

One of the benefits of the new hosting solution is IPv6 is available. So, now is available via both IPv4 and IPv6!

Also, I'm looking for ideas for the site. Are you happy with it as just a casual blog? Do you want more content or collaboration features? Feel free to contact me using the contact form or leave a comment below with any ideas or suggestions. I can't guarantee I'll be able to implement them all, but I will definitely consider each one. 

How to disable useless logs on a Cisco ASA

If you've ever watched the Real-Time Log Viewer in the ASDM, the default settings can make it nearly useless to see specific traffic amongst the noise. Using the filter helps if you are looking for specific traffic, but if you just want to see what what legitimate traffic is scrolling by, then it can be challenging to wade through the copious amounts of data that include logs like:

%ASA-6-302016: Teardown UDP connection 118314 for outside:95.101....
%ASA-6-302015: Built outbound UDP connection 118316 for DMZ...
%ASA-6-305012: Teardown dynamic TCP translation from inside:10.0....
%ASA-7-609001:  Built local-host outside:96.7...

It's pretty simple to exclude these types of log messages from being recorded. Simply login to the CLI and type the following:

How to Start, Stop, and Restart OpenSSH on Ubuntu

Ubuntu Logo

On some Linux systems, typing /etc/init.d/sshd restart will bounce the sshd process. However, on Ubuntu Server 14.04, it didn't seem to work for me. I found the following syntax to get the task done:

> sudo restart ssh
ssh start/running, process 2654

You can use similar syntax to stop or start the process:

> sudo stop ssh
> sudo start ssh

And you can get status of the process by using the status keyword:

> sudo status ssh
[sudo] password for penguin:
ssh start/running, process 2711

How to Configure a Static IP Address and IPv6 Address on Ubuntu Server 14.04

Ubuntu Logo

If you have a new installation of Ubuntu Server, you may want to set a static IP address on it instead of relying on DHCP for a server. It's not as simple as some platforms, but here's the quick and dirty instructions on setting static IPs in Ubuntu Server 14.04:

1. Login with the admin user you created during the install.

2. Check out the contents of the /etc/network/interfaces file:

penguin@wwwsvr07:~$ more /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface # This is an autoconfigured IPv6 interface auto eth0 iface eth0 inet6 auto penguin@wwwsvr07:~$ 

As you can see, it's setup for IPv6 auto config by default in my case.

Caffeine for your Mac

If you have a Mac and have the screensaver enabled, then you must check out the Caffeine utility! It is a simple little app that runs in the menu bar and with one click, it delays your screensaver from starting for a preset amount of time (2 hours). You can also right click on the little coffee cup icon and select how long you want to delay the screen saver.

This is super handy when you are reading something or working on task off screen, but don't want the screensaver to kick in because you need to reference something on screen. If you've never used this before, it's definitely a must have!

How to install a fiber attenuator

Once in a while I find myself doing some awesome work over long distances. In today's case, I've been working on some core and data center interconnects that span 5-35 miles(8-56km) using dark fiber.

One of the connections was causing a warning message in the logs:

%SFF8472-5-THRESHOLD_VIOLATION: Te1/1: Rx power high warning; Operating value:  0.3 dBm, Threshold value: -1.0 dBm.

If you see a simple warning message like this, don't panic, it's a pretty easy fix.

Adobe Licensing Repair Tool

I ran into an error message when trying to run Adobe Acrobat today which read, "Licensing for this product has stopped working" - The pop up message also suggested I needed to open another application that came with the Adobe suite that Acrobat came with, such as Photoshop. So, I tried to open Photoshop and was greeted with the same error message.

A quick web search landed me on a page at with the perfect fix for this problem. The Adobe Licensing Repair Tool is a simple executable that runs a command prompt question/response interface. It asks you if you are sure you want to run it. Once you answer the questions, it cranks through a bunch of stuff in the background magically fixing the broken licensing. Figured I'd put a quick write up on this to help others searching for a fix.

Here's a link to the download:

Convert AF and CS to DSCP values

Memorizing a table of DSCP to AF values is not worth your time when there are easier ways! Check out this simple method to convert an AF value (i.e. AF31) to a DSCP value (i.e. 26). Read on below for how to figure out CS to DSCP values as well.

Let's start with a table showing the AF, CS, and DSCP values:

A Friday "Meet Up" with Jeremy

Hi all -

This Friday, May 9, 2014, I'll be doing my first ever "meet-up" with the kind folks at RouterGod. Stop on by if you'd like to join the conversation!

CCIE Routing and Switching v5 Official Cert Guide Library

With a publication date of August 4, 2014, the CCIE Routing and Switching v5.0 Official Cert Guide Library (5th Edition) is on its way! If you haven't passed the version 4 written exam, this might be a good investment to help out with your studies. I've owned the version 3 and version 4 cert guides and will likely pickup a copy of version 5 when the time to take the written again arrives.

Contents of the Library

Looks like in addition to the two books (volume 1 and volume 2) you get a ton of practice questions on a DVD. That's 1400 pages between the two volumes and "hundreds" of practice questions.


One thing that caught my eye with this publication is

Ninja your way through a running-config

Do you use the command line often? If so, you probably have a set of go-to commands that get you the information you need. One of the staple commands I use is "show run"or show running-config if you want to type it out. The only problem with show run is it gives you the whole config. Often the output is dozens of pages long and can take time to flip through. Here are the shortcuts I use to speed this up..

Forward slash    /

You can use the forward slash after issuing the show run command to search for a specific string of text. I use this a lot when I want to jump to specific range of interfaces. For example, I want to see the configuration for interfaces g0/19, g0/22, and g0/24. I don't feel like typing show run int g0/19 then typing it all over again for the other two interfaces. Simply type show run and then hit /   then type your search string, in this case "0/19" will get you there.

Cisco Memory Component Issues

Cisco recently announced a problem with the memory used in several of their platforms. A specific memory supplier (who Cisco has not named) provided faulty memory modules to Cisco and other vendors between the years of 2005 and 2010.

The Problem

The memory in these platforms degrades over time and up until recently the failure rate was below expected levels. However, recently several Cisco customers have had higher than expected failure rates and as a result Cisco is publicizing the issue to raise awareness.

One way to see if your device has the issue is to power cycle it. If a device does not boot up after being powered back on, then it is likely due to this memory issue.

Affected Platforms

The following platforms may have the faulty memory:

How to Force Quit an application on a Mac

Force Quit

I've been using Macs for years and in my experience it is a very stable platform. I can leave it running for months without issues. However, from time to time an application will get stuck and requires manual intervention to clear it out using the Force Quit feature. There are a couple ways to access Force Quit: one via the menu and the other via keyboard shortcut. Since this happens so rarely, I forget what the keyboard shortcut is and usually resort to the menu. However, sometimes the menu might not be visible (for example, getting stuck in a full screen VNC session). The only way out of this is the keyboard shortcut:

Command + Option + Escape

This will bring the Force Quit menu into view and you should be able to kill the application that has the (Not Responding) listed after it.

If you haven't seen this feature before, click on the Apple menu at the top and select Force Quit:

Cisco ASCII Art

While going through a network inventory of sorts, I came across a device with a banner motd of the Cisco logo. This was on a piece of gear that wasn't deployed by me or anyone I work with, but I thought it was cool enough (in that nerdy sort of way) to share here. At the very least, it's more fun than legal notices..


How to get Wireshark to work in OS X Mavericks

If you have upgraded your Mac to OS X 10.9 Mavericks, you might have noticed that Wireshark (and other apps that utilize the X11 environment stripped from OS X) no longer load. There is a solution that I was able to piece together through trial and error and I'd like to share it here.

First, you need to install the X11 environment. To do this, get a copy of XQuartz and install it.

Second, install a copy of Wireshark

When you go to load Wireshark, it'll complain about not being able to find X11.

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by Dr. Radut