Intel X710 NIC with Packetloss/Flapping-Links
Two years ago, I’ve used multiple Intel X710-DA4 NICs to built an EVPN Setup for my company level66.network. Whilst most of the connections to other peers worked quite well, I’ve had a few links which showed some strange issues. Most commonly the links were reported as flapping from the other peers or they just reported packetloss on their end. After quite some time of troubleshooting, switching optics and using different ports we found the solution. With the default configuration of the Linux driver, the NIC seems to sent out some (maybe malformed) LLDP messages causing issues with some specific networking gear. We were not able to narrow it down to a specific vendor, though. These messages are directly generated on the NIC and are therefore not shown in a tcpdump. That’s why we were not aware of them. ...