In this series here at the StormWind.com Expert Blog, we are going to examine Cisco device commands that many believe we should have learned at the CCNA level. 

First up - the do command. This command allows us to execute show commands from any configuration mode outside of user and exec modes. 

For example:

R1(config-if)# do show ip interface brief 

This might not work in an exam simulation environment, but when in the "real world", this command can be an amazing time saver. 

Video Runtime: 15 minutes
Video Summary:

n this video clip from ICND2 at StormWind.com, Anthony Sequeira guides students through the various methods of routing between VLANs. The configuration of router on a stick is demonstrated.

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Video Runtime: 20 minutes
Video Summary:

In this bonus video for StormWind.com CCNA students - Anthony Sequeira walks you through the site to site VPN configuration.

www.stormwind.com

Which of the following IP addresses fall into the CIDR block of 115.64.4.0/22? (Choose three.)
A. 115.64.8.32
B. 115.64.7.64
C. 115.64.6.255
D. 115.64.3.255
E. 115.64.5.128
F. 115.64.12.128

We know that this subnet mask of 22 falls into the third octet. Converting the third octet of the IP address and the third octet of the subnet mask, we have to the following:

Following Session 3 Part 1

IMPLEMENTING A SMALL NETWORK: Switches and Connectivity

CONFIGURING EXPANDED SWITCHED NETWORKS: VLANs and VTP

CONFIGURING EXPANDED SWITCHED NETWORKS: RSTP and Troubleshooting

Following Session 5 Part 1

IMPLEMENTING A SMALL NETWORK: Routers

IMPLEMENTING AND TROUBLESHOOTING OSPF              

IMPLEMENTING AND TROUBLESHOOTING EIGRP

Following Session 7 Part 1

IMPLEMENTING AND TROUBLESHOOTING ACLs

"A question I have from the ICND1.  Can you have collision domains beyond the switch?  What if we had 2 routers connected, with switches hanging off them, and PC's connected to the switches.  I'd never thought beyond the switch, and I can't justify my answer.  The more I think about it, the worse it gets.  You're only concerned about collision domains up to the switch, right?"

Thanks so much for the awesome question!

In this video blog from stormwind.com, Anthony Sequeira explains how students can get the most out of the real Cisco gear Hands On Labs.