kern.cam.boot_delay=10000 kern.ipc.nmbclusters=1000000hw.igb.num_queues=1 legal.intel_ipw.license_ack=1legal.intel_iwi.license_ack=1hw.pci.enable_msix=0hw.igb.enable_msix=0
dev.igb.0.eee_disabled=1dev.igb.1.eee_disabled=1dev.igb.2.eee_disabled=1dev.igb.3.eee_disabled=1
Try putting a passive switch in between the WAN port and the Fritzbox, just as a test.