This article includes the basic troubleshooting steps for failed Ethernet connections on airFiber devices resulting in FCS errors.
Symptom and Steps to Troubleshoot
- FCS Error counter rising on the switch port.
Symptom Troubleshooting Steps:
FCS errors can be caused by a few different factors:
- Most commonly, the issue is management frames being sent over the wireless interface.
- The airFiber team has been working this software issue out and it will be resolved in a future firmware release.
- Most reports of FCS errors stem from this and this does not affect customer traffic.
- Failing POE or Ethernet cable, or a low-quality Ethernet cable.
- Replacing the cable and/or the POE has solved the FCS errors for many customers in the past.
- Check PoE AC power source.
- Energy coupled into Ethernet cable from RF or magnetic sources.
- Is cable located in a high RF environment and shielded/grounded properly?
- Inline lightning protection devices
- Bypass the device to determine if the FCS issue is resolved.
- Failed/failing Ethernet port on the device itself.
- This is caused by improper grounding practices during the installation and maintenance of the AF24/HD.
A few things that can help:
1. Following proper ground recommendations. Follow this guide to verify your mast and airFiber is properly grounded: airFiber - How to Ground an airFiber Properly.
2. Reduce the length of the Ethernet run. This can be difficult to overcome; Ubiquiti offers two devices that can help:
3. Install Ferrite choke on both ends of the Ethernet run.
4. If all else fails, replace the radio with a known working radio, and double check cable termination and grounding.