Cisco Networking: Graphical Device Configuration Interfaces
Cisco gives you some graphical configuration interface options depending on the class of network device you are using, which varies from Home to Enterprise products. This allows you to avoid the command [more…]
Cisco Networking: Wireshark Data Filters
As a Cisco administrator, unless you establish filters the network protocol analysis tool, Wireshark, will capture everything it sees and keeps which can be a huge amount of data. You have a couple of [more…]
Cisco Networking: Show Version Command on a Switch
On any Cisco network component, the show version command is applicable to any of the hardware using Cisco Internetwork Operating System (IOS), including switches. The [more…]
Cisco Networking: Show Version Command on a Router
Issuing the show version command on a Cisco network router displays hardware unique information. Review the output of the show version command on a router [more…]
Cisco Networking: Show Version Command on a Firewall
Issuing the show version command on a Cisco Adaptive Security Appliance (ASA), often called a network firewalldisplays information unique to that type of hardware. Look at the output of the [more…]
Cisco Networking: Operating Mode Basics
The Cisco Internetwork Operating System (IOS) has an escalating set of network permissions as you move through the prompts or operating modes. When you first connect to a device you will be in User EXEC [more…]
Cisco Networking: User EXEC Operating Mode
When you first connect to a Cisco network router, switch, or firewall, the initial prompt will indicate that you are in User EXEC operating mode. The initial prompt will look like the following [more…]
Cisco Networking: Privileged EXEC Operating Mode
You need to use Privileged EXEC mode if you want to really have update access to a Cisco network system,. To enter this mode from the User EXEC mode, issue the [more…]
Cisco Networking: Global Configuration Mode
To configure a Cisco network device you must enter the Global Configuration operating mode. After passing thru the User EXEC and Privilege EXEC modes you enter the Global Configuration mode by entering [more…]
Cisco Networking: Interface Configuration Mode
Configuring Cisco network devices requires that you enter the Global Configuration mode, but one of the variations in this mode is Interface Configuration [more…]
Cisco Networking: Configuration Saving
Your Cisco network configuration is stored in two main locations: One is in RAM, and the other is in the configuration that is in use, or the running configuration. [more…]
Cisco Networking: Command Help
When you are connected to a Cisco network device with an open console connection, help is available. You are staring at this friendly command prompt, or something similar: [more…]
Cisco Networking: Command Options
The Cisco networking Internetwork Operating System (IOS) has a great context-sensitive Help function, which means the IOS can help you find the specific item you are currently working with. [more…]
Cisco Networking: Command Buffer Basics
If you type the same Cisco networking commands again and again, you can make use of the command buffer, or terminal history. By default the command buffer holds ten lines, but it can be reconfigured with [more…]
Cisco Networking: Connection via Rollover Cable
You most likely make your initial configuration of your Cisco device through a direct serial cable connection via a Cisco rollover cable — the strange blue cable you get with each of your managed devices [more…]
Cisco Networking: Using PuTTY
A terminal emulation program like PuTTY is necessary if you are connecting directly to your Cisco device via a cable or remotely connecting via Telnet or SSH. PuTTY is actively supported, in wide use and [more…]
Cisco Networking: Telnet and SSH Connections
Communicating with your Cisco network devices via Telnet or SSH is considered connecting remotely. This type of connection is typically required because you deploy your configured devices to locations [more…]
Network Basics: Switching and the OSI Model
As you may now be aware, switching fits into the OSI model at Layer 2. With switching and bridging happening at Layer 2, they deal with the MAC address information found in the Ethernet frames. If you [more…]
Network Basics: TFTP Installation and Use
Network administrators must sometimes update the Internetwork Operating System (IOS) file, or firmware of a Cisco device. Using a TFTP server is the most common way of getting a the file to your network [more…]
Cisco Networking: Boot Process Overview
The process of booting up Cisco network devices is pretty straightforward but the details are important to understand. To get started, here is an overview of the Cisco boot process. [more…]
Cisco Networking: Recovering a Device with a Lost Password
You may have an old Cisco router or switch on your storage shelf that you cannot use because you do not have the enable password for it. Well, with your trusty Cisco rollover cable, you can use ROMmon [more…]
Network Basics: IP Network Classes
Network addressing architecture divides the address space for Internet Protocol Version 4 (IPv4) into five address classes. Each class, coded in the first four bits of the address, defines either a different [more…]
Network Basics: Public, Private, and Automatic IP Addresses
Private addressing and Automatic or Dyanmic addressing were developed in response to a dwindling number of available public addresses. To resolve the issue, in 1996, IANA and IETF came up with [more…]
Network Basics: TCP/UDP Socket and Port Overview
To manage the connection between application layer network protocols, TCP and UDP use ports and sockets. TCP and UDP operate at the host-to-host layer in the IP communication model and provide host-to-host [more…]
Network Basics: TCP/IP and OSI Network Model Comparisons
Internet Protocol (IP) version 4 (IPv4) is the current standard IP protocol used with TCP/IP — Transmission Control Protocol/Internet Protocol — which is the protocol for Internet addressing. Like the [more…]










