Update to my October post in LP#1667750 which turned out to be a separate issue (1Gbps mode dropouts) on the same adapter.
Dell Precision 5520 and BIOS 1.7 using TB16. This is on Ubuntu 16.04.3, kernel 4.13.0 The issue is still present. I tried limiting the bandwidth using `ethtool -s eth0 speed 100 duplex full autoneg on` and also as described in this blog post: http://mark.koli.ch/slowdown-throttle-bandwidth- linux-network-interface and it *seems* to be making the issue less apparent, but still present. $ for i in 1 2 3 4; do curl -s http://old-releases.ubuntu.com/releases/17.04/ubuntu-17.04-server-amd64.img -o $i.iso; md5sum $i.iso; done 2641b55ed2e203861fb6f642bb05b8f7 1.iso 63f41e8b8e4e5ad1909637dbd2efd849 2.iso ^C% $ sudo ethtool -s eth0 speed 100 duplex full autoneg on $ for i in 1 2 3 4; do curl -s http://old-releases.ubuntu.com/releases/17.04/ubuntu-17.04-server-amd64.img -o $i.iso; md5sum $i.iso; done 4672ce371fb3c1170a9e71bc4b2810b9 1.iso 4672ce371fb3c1170a9e71bc4b2810b9 2.iso 4672ce371fb3c1170a9e71bc4b2810b9 3.iso 4672ce371fb3c1170a9e71bc4b2810b9 4.iso $ for i in 1 2 3 4; do curl -s http://old-releases.ubuntu.com/releases/17.04/ubuntu-17.04-server-amd64.img -o $i.iso; md5sum $i.iso; done ed13e9c6c45f027f686000eccce42254 1.iso 4672ce371fb3c1170a9e71bc4b2810b9 2.iso ^C% Next, I tried disabling offloading as described in LP#1667750. Keep in mind, the device still needs to be in 100Mbps mode or you will experience dropouts in addition to any packet corruption issues that you may run into. $ sudo ethtool --offload eth0 tx off Actual changes: tx-checksumming: off tx-checksum-ipv4: off tx-checksum-ipv6: off tcp-segmentation-offload: off tx-tcp-segmentation: off [requested on] tx-tcp6-segmentation: off [requested on] $ sudo ethtool --offload eth0 rx off $ for i in 1 2 3 4 5 6; do curl -s http://old-releases.ubuntu.com/releases/17.04/ubuntu-17.04-server-amd64.img -o $i.iso; md5sum $i.iso; done 4672ce371fb3c1170a9e71bc4b2810b9 1.iso 4672ce371fb3c1170a9e71bc4b2810b9 2.iso 4672ce371fb3c1170a9e71bc4b2810b9 3.iso 4672ce371fb3c1170a9e71bc4b2810b9 4.iso 4672ce371fb3c1170a9e71bc4b2810b9 5.iso 4672ce371fb3c1170a9e71bc4b2810b9 6.iso I left it to run over lunch at 25 loops to be sure and it's working fine. This weekend I may be able to test this on a 2017 XPS 9560 (non- DE) too. Thanks for the workaround and looking forward to the patch making it to Ubuntu repos. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1729674 Title: TB16 dock ethernet corrupts data with hw checksum silently failing Status in Dell Sputnik: Triaged Status in linux package in Ubuntu: In Progress Status in linux source package in Artful: Fix Committed Status in linux package in Fedora: Confirmed Bug description: It looks like TCP rx and tx checksum offloading is broken on the TB16 dock's ethernet adapter. For example downloading a large file such as the Ubuntu ISO, and then running an md5sum on it yields the incorrect md5sum. This is because rx-checksumming: on tx-checksumming: on and both set to on by default. Running sudo ethtool -K <TB16 eth device> tx off rx off, allows the download to complete correctly. This is very bad since this can cause very bad untrustworthy behavior. This was conducted using an Dell Precision 5520 on Ubuntu 16.04+linux- generic-hwe-16.04-edge. Thank you To manage notifications about this bug go to: https://bugs.launchpad.net/dell-sputnik/+bug/1729674/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
