Tag Archives: Cisco
Spanning Tree – the Roots Go Deeper!
While I have posted a couple of blogs regarding spanning-tree, the Layer 2 loop prevention mechanism that runs on Cisco switches, I wanted to post one with a few more switches and a bit more detail on the step-by-step process. … Continue Reading
Changes to the ICND1 Curriculum from Cisco! Etherchannel Port Aggregation
As I promised last time, I will be providing more updates regarding the differences between the previous CCNA track and the new CCNA Routing and Switching track announced by Cisco on March 26th. One of the major differences is that … Continue Reading
Exploits Against Legacy Encryption – A Conversation with Cisco
You should already realize that you cannot just change your standard encryption algorithms and key lengths on a moment’s notice. Those are decisions that you made after careful research and testing. So while you might have some cryptography in place … Continue Reading
Deciphering Layer 2 devices and the ARP process
So you are troubleshooting the network and PING from one device to another. A reply is received. Great! Connectivity has been restored. But what happened behind the scenes? As long as the two devices are on the same network or subnet, the proof of … Continue Reading
How to configure OSPF authentication on Cisco routers
Perhaps you have heard that it is a good idea for your routers to verify the sources of routing update information. Much like when you call your bank and you ask them for your current balance, they want to know … Continue Reading
How to redistribute routes using Cisco route maps and IP prefix lists
In previous blogs I have covered both ip prefix lists and route maps How to interpret Cisco IP prefix lists and How to Decipher Cisco Route Maps. Now I want to take some of what has been discussed and make a … Continue Reading
Cisco does something “Meraki-lous”
As you may have heard by now, Cisco has acquired Meraki – a company with wide appeal to non-enterprise-sized companies. The main reason Meraki appeals to smaller companies is that its Wi-Fi product line allows companies to deploy and expand wireless … Continue Reading
CISCO Aspire – A fun CCNA Certification Game and Study Guide
Greetings to all who are reaching for a CCNA certification, there is a study aid available on the Cisco website for those with a Cisco (free) login. It’s called Cisco Aspire CCNA Edition. Here is an introductory video: You can … Continue Reading
Cisco EIGRP authentication – what is the key?
How many times have you heard that two potential EIGRP neighbors with md5 authentication configured will neighbor up even if they are not using the same key in their key chains? Several Cisco texts have made this comment. I decided … Continue Reading
More Cisco CCNA Certification Study Tips and Aids
As you may know if you read my blogs or have been in my classes, I am a big believer in memory aids, or mnemonics. I have a previous blog; Cisco certification exam memory aids – My favorite mnemonics which … Continue Reading
Cisco’s EIGRP metric – fact and not so fact
As a quick reminder from my previous blog post, let’s take a look at the full Enhanced Interior Gateway Routing Protocol (EIGRP) metric formula: The EIGRP fomula simplifies (using default k-values) to: 256(min bandwidth + cumulative delay) To determine min … Continue Reading
Spanning Tree Protocol (STP) has been around the block
Last time we were introduced to the basics of the Spanning Tree Protocol, the loop prevention mechanism that has been with us since 1985. STP results in a network where some ports are transmitting frames and some are blocked (hence the … Continue Reading
Cisco EIGRP metric calculation simplified– the eyes have it!
There are numerous sources online which discuss Cisco’s Enhanced Interior Gateway Routing Protocol (EIGRP) metric formula and its computation. My goal today is to present the formula in a way that is more pleasing to the eye so it is … Continue Reading
Cisco news – CCNA assessment exams, prices, Cisco careers and CCSI Exam retakes
As I mentioned in a previous blog, Cisco is revamping many of their virtual labs and re-releasing them. In particular, I am eager to see how the new SWITCH labs are received by users since Cisco is doing a complete … Continue Reading
Cisco Live with Jeremy Cioara – June 13th
Interface Cisco Instructor Jeremy Cioara will be presenting: BRKCRT-9103 CCNA Voice: Real World Overview and Certification Preparation at Cisco Live in San Diego, California from 3:15pm – 5:15pm PT on June 13, 2012. This session covers the basics of IP … Continue Reading
Cisco Learning Labs update for CCNA ICND-1 and ICND-2
For those of you who haven’t seen it, Cisco offers the ability to do the labs for ICND-1 and ICND-2 (and other labs as well) in a virtualized lab environment. While the most likely targets for this offering are students … Continue Reading
Understanding Cisco routing tables with route print to find my IP
Have you ever looked at the output of the show ip route command on a Cisco router and tried to figure out how the router ‘makes up its mind’? If you troll the Cisco website articles for information on the … Continue Reading
Time savers and cool Cisco IOS tips
How about some cool tips designed to make your life easier maybe a little more fun at the same time? Today I want to share a couple of things you might find useful or downright mind blowing (if you’ve never … Continue Reading
What is IPv6 and when can we expect it to take over the world?
While the title sounds like a quote from Pinky and the Brain, there is no reason to fear. It is not a hostile takeover. Yet human beings seem to be notoriously poor at predicting the future. It’s always much easier … Continue Reading
Folding for Subnetting Professionals – subnetting a subnet and number of hosts per subnet
Now that we have covered subnetting to create just two networks and moved on to creating multiple subnets with Class B and Class A networks, let’s finalize this blog series topic with one more installment. Our goal in this blog … Continue Reading
