I tested http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.19-rc7-vivid/ an the state of the SACK packes is still invalid and thus those packets are filtered by the firewall which leads to stalling scp connection.
** Tags added: kernel-bug-exists-upstream ** Changed in: linux (Ubuntu) Status: Incomplete => Confirmed -- 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/1417157 Title: scp transfers stalls and aborts because of SACK packages with invalid state Status in linux package in Ubuntu: Confirmed Bug description: There is an existing bug report at red hat websites that exactly discribes what happens to my ubuntu server installation. https://bugzilla.redhat.com/show_bug.cgi?id=161898 I can confirm that this bug is affecting ubuntu 14.04 servers as well as debian installations we are running in our university network. I can further confirm that all workarounds stated in the last post by Chris (2014-02-20 12:17:53 EST) work and he nailed pretty much all my findings on our servers. So please read the last post by Chris. There is probably also a relation to this launchpad issue: Bug #1388786, but I'm not shure about that. Is there any way you can provide me with a linux kernel that solves this issue. I'm willing to test and report here. Thanks in advance StVO --- AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Feb 2 13:26 seq crw-rw---- 1 root audio 116, 33 Feb 2 13:26 timer AplayDevices: Error: [Errno 2] No such file or directory ApportVersion: 2.14.1-0ubuntu3.6 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: Error: [Errno 2] No such file or directory DistroRelease: Ubuntu 14.04 HibernationDevice: RESUME=UUID=5fbc1974-f145-443b-adf9-708d9b8d8b21 InstallationDate: Installed on 2012-07-17 (930 days ago) InstallationMedia: Ubuntu-Server 12.04 LTS "Precise Pangolin" - Release amd64 (20120424.1) IwConfig: eth0 no wireless extensions. eth1 no wireless extensions. lo no wireless extensions. MachineType: HP ProLiant DL380p Gen8 Package: linux (not installed) PciMultimedia: ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-45-generic root=UUID=4ccd0afd-59be-4acb-bdc6-34f2699db5b9 ro intremap=no_x2apic_optout reboot=bios ProcVersionSignature: Ubuntu 3.13.0-45.74-generic 3.13.11-ckt13 RelatedPackageVersions: linux-restricted-modules-3.13.0-45-generic N/A linux-backports-modules-3.13.0-45-generic N/A linux-firmware 1.127.11 RfKill: Error: [Errno 2] No such file or directory Tags: trusty Uname: Linux 3.13.0-45-generic x86_64 UpgradeStatus: Upgraded to trusty on 2014-09-05 (150 days ago) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True dmi.bios.date: 02/25/2012 dmi.bios.vendor: HP dmi.bios.version: P70 dmi.chassis.type: 23 dmi.chassis.vendor: HP dmi.modalias: dmi:bvnHP:bvrP70:bd02/25/2012:svnHP:pnProLiantDL380pGen8:pvr:cvnHP:ct23:cvr: dmi.product.name: ProLiant DL380p Gen8 dmi.sys.vendor: HP To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1417157/+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