David’s Cisco Networking Blog

July 23, 2008  9:15 PM

Cisco IOS what, when, & where questions

David Davis David Davis Profile: David Davis

Here are 3 Cisco IOS questions that you should know the answer to:

Question: What is the purpose of ports?
Answer: Port numbers allow hosts to identify which application processes send and receive data inside TCP and UDP datagrams.

Question: When an engineer wants to verify the application layer (that’s Layer 7) software between source and destination stations, which command should he use?
Answer: Telnet. Telnet is an application that would test all seven layers of the OSI model.

Question: Where should you place standard ACLs in the Network?
Answer: Standard ACLs should be placed as close as possible to the destination to prevent unintended traffic from filtering to your other networks.

July 22, 2008  9:11 PM

Cisco focuses on Russia and CIS

David Davis David Davis Profile: David Davis

It amazes me what a global company Cisco is. How can they focus on China, Russia, and everywhere else in the world, all at the same time?

I found this news interesting, from Cisco’s website:

Cisco recently announced a venture capital investment in Almaz, Russia for $60 million dollars that will focus attention on Russia and The Commonwealth of Independent States (CIS). Essentially, the Almaz partners seek out small and medium sized companies looking for technologies in media and telecommunications. Cisco then pursues startups for these companies. Cisco has already been doing similar ventures in the Russian market with a Russian online company named Ozon.
For more information on this new partnership, please see the Cisco article, Cisco Announces Investment in Venture Capital Fund to Focus on Russia and CIS.

July 22, 2008  9:09 PM

Cisco will assist China after major earthquake

David Davis David Davis Profile: David Davis

While Cisco seems to be a very humane company, they also have a lot invested in China. Because of this, their intentions are two-fold.

According to the latest Cisco news, Cisco has announced a $45 million three-year commitment to support reconstruction efforts in China’s Sichuan Province. They had a major earthquake there recently which all but destroyed the Province.  Cisco will be working with public and private partnerships for the health, education, and communication needs of these Chinese people.
For more information on this story, please see the Cisco article, Cisco to Provide US $45M (RMB 300M) to Support Rebuilding Efforts in China’s Earthquake-Affected Sichuan Province.

July 22, 2008  9:06 PM

How to restore the backup configuration file from a HyperTerminal Emulator

David Davis David Davis Profile: David Davis

In a previous blog entry (Using Text Capture in HyperTerminal to backup and restore your Cisco IOS configuration) I demonstrated how to use the Hyperterminal Text Capture to backup your Cisco IOS configuration.

In this post, you can see how to restore that Cisco IOS configuration. Here is how you do it, step by step:

a. Log into the router using HyperTerminal.
b. Go into router global config mode.
c. From the HyperTerminal window, choose Transfer / Send Text File.
d. Select the name of the file for the saved backup configuration.
e. The lines of the configuration are being displayed into the router. Look for any errors.
f. After the config is complete, press the CNTL-Z keys to exit global config mode.
g. Restore the startup configuration with the command, copy running-config startup-config.

July 21, 2008  9:04 PM

Cisco spearheading a new organization to help with ever growing security concerns

David Davis David Davis Profile: David Davis

The Industry Consortium for Advancement of Security on the Internet (ICASI) is very much overdue by those of us who are working so hard to protect our networks. This is a non profit  organization that is organized by 5 major corporations, Cisco being the first, that allows companies to come together on issues relating to viruses and other security cyber threats.
The organizations philosophy is committed to improving corporate threats, among other things,  by collaborating with other vendors with similar issues.

For more information on ICASI, please see the following Cisco article:

IT Vendors Create Forum to Drive Global Security

July 20, 2008  9:01 PM

5 Cisco IOS Terms that you should know

David Davis David Davis Profile: David Davis

When preparing for your Cisco CCNA or just learning the IOS, there are a number of terms that you need to know. Here are 5 of them:

1. Administratively Down – One possible interface on a Cisco router.
2. Assignable IP address – An IP address that can be assigned to an interface excluding reserved IP addresses in a subnet.
3. Bootstrap – The program that a computing device loads, using hardware, to initialize enough software to look for and load the fully functional OS.
4. Cisco IOS – The operating system that runs in a Cisco router.
5. Cisco IOS image – A single file that contains a complete copy of the IOS.

July 19, 2008  8:57 PM

Using Text Capture in HyperTerminal to backup your Cisco IOS configuration

David Davis David Davis Profile: David Davis

While you can download your Cisco IOS configuration using TFTP, this requires networking to be configured and operational.

Another alternative is to use HyperTerminal’s text capture to backup your configuration. Let’s find out how…

Here is how to use it, step by step:

a. In the HyperTerminal window, choose Transfer / Capture text.
b. Specify the name for the text file.
c. Click the Start button to start capturing the text.
d. Display the configuration to the screen by entering show running-config.
e. Press the Spacebar when each __More__ prompt appears.
f. When completed, stop the capture by choosing Transfer / Capture Text / Stop.

You can then take the text file created by hyperterminal and use it as a backup for that router or switch!

July 17, 2008  8:53 PM

Three Cisco IOS Tips…

David Davis David Davis Profile: David Davis

I commonly get questions from junior admins about the Cisco IOS. Here are 3 tips that I came up with:

1. How do you find available options on a command? (get help)

Use the ?.

Example: Options on an interface command:
R1# show i?
R1#: show interfaces ?

2. How do you ping an address?

R1#: ping  (enter)

And how do you do an advanced ping?

Easy, just type “p” or “ping” and press enter. Then, answer the questions as they are asked.

3. How do you copy an IOS file from TFTP into Flash Memory?

R1# copy tftp flash  (enter)

(and fill out the questions as they are asked)

July 15, 2008  8:48 PM

What is Cisco doing to go Green?

David Davis David Davis Profile: David Davis

Cisco recently announced that they will reduce absolute greenhouse gas emissions by 25% by the year 2012. Jim Sullivan, director, U.S. Environmental Protection Agency Climate Leaders program quotes, “Looking at the high-tech industry in general, data center energy use is rapidly increasing – consuming 61 billion kWh in 2006 and projected to increase to 100 billion kWh in 2011”.

How are they going to do this? They are going to focus on their current technologies such as TelePresence and WebEx suite tools. These programs will eliminate the need for so much travel thereby reducing gas emissions. Another thing that Cisco is doing is in the area of their employees’ work place. Instead of individual cubicles, Cisco has fostered a more open layout utilizing their Technologies of Cisco IP Communicator among others.

For more information on this office design study, please see Office Design Case Study: How Cisco Designed the Collaborative Connected Workplace Environment.

Cisco hopes that the benefits of this green concept will flow into other companies. As the gas emissions decrease, so will energy reduce thereby adding to shareholders value.
For the complete story on how Cisco pledges to reduce greenhouse gas emissions, please see The Innovative Power of the Network: Helping Transform How the World Tackles Environmental Challenges.

June 30, 2008  9:11 AM

Understand the OSI model to become a better Cisco troubleshooter

David Davis David Davis Profile: David Davis

While the OSI Model may seen like some useless & arcane topic that you only study to get your CCNA, I believe it is very valuable in understanding how networks work and how to troubleshoot them. In one of my most recent articles, I cover the OSI model and explain how you can use it to better troubleshoot your Cisco network.

To read the full article, visit:  Understand the OSI model to become a better Cisco troubleshooter

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