Tag Archives: topology

What Happens when there are duplicate MAC Addresses. How many MAC Addresses can a Switch learn?

This post is from our Cisco CCNA Training Course. Instructor Mark Jacob was presenting a Q&A Session in our ICND1 CCNA class and answered a question regarding MAC Addresses and when they get associated to devices. Transcription: What issues arise if there are duplicate MAC addresses? MAC addresses are important. Let’s say I’m a PC … Continue reading What Happens when there are duplicate MAC Addresses. How many MAC Addresses can a Switch learn?

How to create a simple network topology using Cisco’s VIRL

For those of you who are interested in investigating Cisco’s VIRL product, I have created a blog to show how to create a very simple network topology.  You may already use other lab-it-up solutions such as GNS3, Packet Tracer, Boson’s NetSim, or something else.  I promised that I would blog about VIRL once I had … Continue reading How to create a simple network topology using Cisco’s VIRL

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 bandwidth and cumulative delay, use the following information: Delay is computed as the cumulative delay … Continue reading Cisco’s EIGRP metric – fact and not so fact

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 easier to follow the values as they get crunched through it. The following diagram is … Continue reading Cisco EIGRP metric calculation simplified– the eyes have it!