The solution is to unplug the fiber and reinsert it into the SFP module interface until a “click” sound is heard, indicating the fiber connector and SFP module are properly connected. Contamination or damage on the fiber end face requires the use of a fiber end-face. I have been trying for 2 days to troubleshoot a fiber connection that I need between an existing Arista and a Cisco 3650. Right now, I can't get a lot of equipment to connect all with SFP-LH-SMD transceivers. This is a high-level summary of the situation, but it's really strange (and YES, I have. The SFP/Media Converter is designed for easy use in optical fiber transmission. When the connection does not work as expected after we set it up according to the Installation Guide, we need to do some troubleshooting. Are you saying that the switch/transceiver reports that is is receiving light on the fiber being used for Rx? If light is getting from A to B on one fiber but not the other, it's very possible you have a dirt, dust, or other particulate blocking light at one of the patch locations. FCS and CRC errors occur on the port. The self-loop of a single fiber cannot go Up. Check whether the rates, duplex modes, and negotiation modes of optical ports at both ends are the same. If not, configure. When SFP failure occurs, it's important for technicians to figure out the reason immediately and repair it, otherwise, the 1 Gigabit link may break out.
