How do detect unplugging ethernet cable FTP connection


With the Rabbit BL2600 Wolf board i managed to set up a telnet connection using one of the samples that came along with the Rabbit board. Unplugging the ethernet cable goes undetected by the BL2600. What function can be used to detect unplugging of the cable with a telnet session? The idea would be that the BL2600 starts listening for new connections once the connection is lost, but therefor it should obviously know when the connection is lost. Help is appriciated.