In computer networking, specifically Internet Relay Chat, netsplit (sometimes netburp) is a term used to describe the disconnection of a given node from the previously established network.

Consider the graphic below, which will represent the computer network.

Each line represents an established connection between the two nodes; each node represents either a server or a user on the network. Therefore, the server C is connected directly to A, which is also connected to B and D.

If a disruption in the connection between C and A occurs, the connection may in result be terminated. This can occur either by a socket (the device in which the server is connected) producing an error, or by excessive lag in which the far server A anticipates this case (which is called a timeout.)

When the connection between A and C is severed, users that were connected to other servers which are no longer reachable on the network appear to quit. For example, if user Sara is connected to server A, user Bob is connected to server B, and user Bar is connected to C, and C splits (disconnects) from A, it will appear to Bar as if Sara and Bob both quit (disconnected from the network), and it will appear to both Sara and Bob that Bar quit. This happens because the servers in which they are connected are informed of the change in the network status, and update their local information accordingly to display the change.

Later, server C may relink (reconnect) to a server on the network and the users who appeared to have quit will rejoin; the process of sending this updated information to all servers on the network is called a netburst.