Automatically determining a link speed between link partners using a multispeed fiber module. An embodiment solves the problem of how to determine the highest common link speed between short range (SR)/long range (LR) fiber link partners when at least one of the link partners is using a multispeed fiber module. In an embodiment, a multispeed fiber module comprises a module that is capable of both 10 gigabit (GB) per second Ethernet and 1 GB per second Ethernet or lesser data transfer speeds over a fiber optical link. In an embodiment, the method comprises trying each link speed in a known succession, from highest supported speed to lowest supported speed. In an embodiment, an initiator link partner “blinks” a transmit laser, which alerts the link partners that a link speed determination session is being initiated. By automatically determining link speed, the user is relieved of the necessity to manually configure the link speed.