Communication apparatus and path switching method

A communication apparatus on a network having ring topology and connecting a plurality of communication apparatuses such that adjacent communication apparatuses are connected through a plurality of lines, the communication apparatus comprising:

• a first detecting unit that detects failure occurring in a line that is among the lines and included in a relay path set between the communication apparatus and a communication apparatus on the network;
• a switching unit that, when the first detecting unit detects failure, 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 that detects failure occurring in a line included in the relay path switched to by the switching unit;
• and
• a resetting unit that, when the second detecting unit detects failure, resets the relay path using, among the lines, a line where no failure has been detected.