KVM switch

A KVM switch is a device that allows managing several servers and computers from one keyboard, monitor and mouse. It is used in server rooms and data centers to save space and provide convenient access to equipment.

What is a KVM switch

KVM (Keyboard, Video, Mouse) is a switch that combines the keyboard, monitor and mouse ports of several computers. The administrator connects one set of keyboard, monitor and mouse to the KVM and switches between servers by pressing keys, a button on the case or through an on-screen menu. Such a switch eliminates the need to install a separate monitor and keyboard for each server, saving space in the server rack and simplifying management. KVM is transparent to the operating system: servers “see” an ordinary keyboard, monitor and mouse, so no special drivers are required.

Types of KVM switches

By design, desktop KVMs for several computers and console ones built into a rack with a retractable screen are distinguished. By connection method — local (cable) and remote (IP-KVM), which allow managing servers over the network from anywhere. Modern models support several users simultaneously, switching via hot keys, automatic discovery of computers and differentiation of rights. KVMs with PS/2, VGA, DVI, HDMI and DisplayPort interfaces are distinguished, as well as models working with a touchscreen and sound.

What is an IP-KVM

IP-KVM is a KVM switch with a network interface that allows the administrator to work with a server remotely: open the BIOS, boot the operating system and fix failures without physical access to the rack. The signal from the monitor and keyboard data are transmitted over the network, so control is possible from any computer or laptop. IP-KVM is critical for banking and corporate data centers, where the administrator must quickly restore the service without traveling to the facility. Access to the IP-KVM is protected by encryption, authentication and differentiation of rights to exclude unauthorized interference in the infrastructure.

How to choose a KVM switch

When choosing, take into account the number of servers, their interfaces (VGA, HDMI, DisplayPort), the need for remote management and the number of simultaneous users. For a rack with several servers, a local KVM with 8–16 ports is enough; for a distributed infrastructure, an IP-KVM with encryption and power redundancy is chosen. Evaluate the convenience of switching: hot keys, an on-screen menu and a function for automatic discovery of computers. The quality and length of cables affect signal stability on long lines. Built-in access audit and compatibility with different server hardware vendors are also important.

KVM and information security

Remote access through an IP-KVM gives full control over the server, including the BIOS and OS boot, so it belongs to critical infrastructure. Access is protected with multi-factor authentication, channel encryption (TLS/SSH), role differentiation and session logging. IP-KVM sessions are usually connected through a separate network segment or VPN to exclude data interception. For organizations with high security requirements, auditing of administrator actions and automatic termination of sessions by timeout are provided. A physical KVM without network access is safer from the point of view of remote attacks, but requires the operator's presence in the server room.