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?
Have you had a chance to build some projects in the new rev of GNS3? If you have not done so yet, I would highly recommend heading over to GNS3 and downloading it. In this blog I will presume that you have already taken the steps to install it. My goal is to demonstrate how similar … Continue reading CCNA R&S prep, GNS3 1.x, and Router-on-a-stick!
So you are maintaining a medium-sized network and you want to route traffic between your VLANs. What are your options? You can place one router interface in one VLAN and another router interface in each of the additional VLANs, but this is horribly inefficient use of router resources. Another option is to use Layer 3 … Continue reading Walk softly and carry a Router-on-a-stick! (ROS)
This blog will address the configuration of DHCP pools on Cisco routers as well as how to verify that addresses from the correct pools have been distributed. I have built a small networking environment with which to test and troubleshoot the config, so let’s get started. Here is a diagram of the network: What I … Continue reading How to configure DHCP pools on Cisco routers
Clearing out a Cisco switch configuration is always a pain because VLANs are kept in a seperate file from the startup-config (NVRAM). There's two ways to clear a switch back to the factory defaults – the easy way and the REALLY easy way: The easy way – Switch# write erase Switch# delete flash:vlan.dat Switch# reload … Continue reading Completely Clearing a Cisco Switch…The Easy Way!