Patient: Intel i350 ethernet built into Supermicro X9DAi motherboard.
Symptoms: constant disconnects on upload (files to FTP / sending emails w. attachments / using services like dropbox or wetransfer / browser uploads / ... ), so only restart helps.
Treatment: edit info.plist of AppleIGB.kext (wherever u use it) and change the NETIF_F_TSO key under i350 dictionary to false:
<key>i350</key> <dict> <key>CFBundleIdentifier</key> <string>com.insanelymac.driver.AppleIGB</string> <key>IOClass</key> <string>AppleIGB</string> <key>IOPCIMatch</key> <string>0x15218086</string> <key>IOProviderClass</key> <string>IOPCIDevice</string> <key>NETIF_F_TSO</key> <false/> </dict>
Restart your machine and enjoy full power of your ethernet never ever crashing on large packet upload.
FYI I use hnak's AppleIGB kext (5.3.5):
located at CLOVER/kexts/10.10 on my system's EFI partition.
Technical background (in Linux):
Fred says: thats all!