Understanding the Difference Between a KVM Switch and Serial Console

Rick Gonedes
June 1, 2017

At first glance, KVM switches and serial consoles can seem quite similar. Both are tools for managing your IT infrastructure. However, the difference between them comes down to what types of equipment each tool can manage. When you understand the capabilities of each, you get a better idea of which is the right tool for the job.

In the simplest terms, KVM switches control servers and PCs with console servers control other serial and network-connected devices like routers and firewalls. A KVM switch allows you to connect to computer devices, such as PCs, servers, and workstations. A console server allows you to access serially-managed devices and control them via a Command Line Interface (CLI).

What a KVM Switch Can Do

KVM stands for "keyboard, video, mouse," and allows you to control multiple computers from a single keyboard, mouse, and monitor. These switches are often used to manage racked servers where a number of servers are placed in a single rack. By pushing a single button on the KVM switch, the administrator can change control from one server to another, easily accessing each one.

Some KVM switches are for local use and can control nearby servers and computers from within the room, in another room, or on another floor. IP KVM switches offer IP-based remote access, which means that you can control multiple servers and computers from potentially anywhere in the world that has an internet connection.

Local KVMs allow you to eliminate the cost of a dedicated keyboard, mouse, and monitor for each computer. This also eliminates the clutter of excess devices and cords in your server room, allowing for a safer and cleaner space.

These switches allow you to perform functions such as rebooting the computers. A KVM switch provides a direct hardware connection that allows you to display the BIOS of a computer on reboot to make adjustments as needed.

What A Serial Console Server Can Do

While KVM is specifically for controlling computers, a console server can access devices with RS-232 serial ports. These are designed to work with "headless" devices such as routers, LAN switches, Unix® and Linux® servers, firewalls, power distribution units, uninterruptible power supply systems, and storage systems. You'll also see console servers referred to as terminal servers.

A console server will typically have many different ways to connect to the console of the serial device.  These range from web-based user interfaces to SSH programs such as putty. These can be used to complete tasks such as updating the firmware in hardware like routers or to view the temperature of a device to assure that it is working within safe parameters.

A number of models have built-in modems or 3G cellular access so that you can always get connected to the devices you need to. Like an IP KVM switch, these tools will allow you to access your devices whether you are in the same room, in another building, or in another part of the world. Different models will offer anywhere from a handful of ports to 32 or 48 ports so that all of your devices can be managed.

Which device suits your needs best will depend on what equipment you need to control? While one may offer all of the functions you need, you may need more than one device to handle all of your computers and electronics. Need help picking the right one? Get in touch today to discuss the best option for you at http://www.raritan.com/contact/sales.