Introduction
In this post I will discuss what are the Top 5 most powerful cisco commands. The 5 commands I will discuss in this post are:
- reload
- en (enter privileged EXEC mode)
- conf t (configure terminal)
- sh int (show interface)
- interface (int)
lets get started.
Reload
This is possibly in my opinion the strongest Cisco Command, as this causes a reload of the device. This means it affects production and should use this command wisely. If using this command in a home lab its fine, but keep in mind if you are in production. Using this command will cause a small outage, as the device will need to boot (typically 5 minutes).
When to use?
Reload command can be used in situations were the switch/device is acting weird. Changes are that rebooting it could fix some of the issues. An example is a slight power outage, causing the switch to go into an abnormal state. Sometimes even connecting to the switch console cable, you will notice a lag. This lag could be resolved by a simple reload. Unless the lag issue is deeper such as faulty chipsets, or a failing switch. This scenerio will require assistance by the vendor. If your devices do not have warranty, it might be time to scroll through ebay to find some deals.
“en” (Enable)
This command is called Enable, and is what you use to enter privileged EXEC mode. Think of it as Admin mode. Once in this mode a whole list of new commands appear to the user. An example of a command is conf t (Configue Terminal). I will talk about this command later in this post.
When to use?
This command is best used when trying to change a setting on the switch, or adjust a network configuration. An example would be a VLAN change, or an Interface change. Another usage for this gateway command is, changing hostname, or adding a banner.
conf t (Configure Terminal)
This command is used for configurations. You would use this command before using interface command, or any network configuration command. I will talk about the Interface command later in this post.
When to use?
This command is used when attemping to change VLAN of an interface, or even actively changing network configs inside of a VLAN. This command is used as the gateway to create vlans, change interface names, and even delete interfaces/vlans. You can even go as far as setting domain name servers, NTP configurations, and routing protocols (routing commands depend if device is a switch (L2, L3), or a Router.
“sh int” (Show Interface)
This command is used for information purposes. you can use this command to check status of interfaces, IP information, see packet counts, and even see if the interface is up or down state. It is a very useful tool for troubleshooting, especially if you are experiencing connection issues on an end device. This command is your first tool in determining if this is a network issue, or a device/application issue.
When to use?
Use this command when troubleshooting networking connectivity, checking packet counts, searching for interface/vlan information,
“int” (Interface)
This command is used after entering conf t, here you can go inside specified interfaces, or vlans and change everything. From names, and details, to IPs, and gateways. In this command you can even go deeper into Spanning Tree Protocol Commands. You can even assign VLANs to an interface, or even add security to interfaces.
When to use?
Use this command when configuring interfaces, or VLANs.
Take Away
This is just a basic top 5 command post. It is meant to start opening the door to more commands. I feel like I had barely touched the surface on these commands. The next post will focus on the “show” command. A powerful troubleshooting command, and possibly my most used command.
