I can reproduce this error too. The environment is a full CISCO network with vmware ESXi hosts and ubuntu 14.04 guests.
Also here downloads to about 2MB are going somehow fine, but all which is taking longer (or more MB to transfer) is dropping to a very low bandwidth. Very often without any bits transmitted at all. The issue is, that it looks like if pakets are received in random (not serial order) the SACK seems to be too aggressive and kicks the high speed of the transmission -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1388786 Title: TCP stale transfer with erroneous SACK information To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1388786/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs