In a communication apparatus on a network having ring topology and connecting plural communication apparatuses such that adjacent communication apparatuses are connected through plural lines, a first detecting unit detects failure occurring in a line included in a relay path set between the communication apparatus and another communication apparatus on the network. When the first detecting unit detects failure, a switching unit switches the relay path to a relay path connecting the communication apparatuses on the network in a direction opposite to the relay path originally set. A second detecting unit detects failure occurring in a line included in the relay path switched to by the switching unit; and when the second detecting unit detects failure, a resetting unit resets the relay path using a line where no failure has been detected.