On Wed, 3 Apr 2019, Adam Eijdenberg wrote:> On Wed, Apr 3, 2019 at 9:43 AM Damien Miller <djm at mindrot.org> wrote: > > Could you try turning off IPQoS setting (ssh -oIPQoS=none ...) and seeing > > whether that makes any difference? > > Yes - setting -oIPQoS=none on the client allows for a successful > connection to the server. > > Would you still like me to check on the other things or is that enough > to go on with?No - it looks like a middlebox in Amazon's network might be getting confused when the DSCP value changes during the connection. Thanks a lot for helping to chase this down. Cheers, Damien
Sigh - I think the issue may lie closer to my end. Something that I did not mention, as it didn't seem relevant at the time, is that I'm doing my testing from an Ubuntu running inside a VMware VM on a Windows host. Now we know it's an IPQoS issue, I've found the following, suggesting it might be a VMware networking issue: https://communities.vmware.com/thread/597244 Sorry for the noise. On Wed, Apr 3, 2019 at 10:00 AM Damien Miller <djm at mindrot.org> wrote:> > On Wed, 3 Apr 2019, Adam Eijdenberg wrote: > > > On Wed, Apr 3, 2019 at 9:43 AM Damien Miller <djm at mindrot.org> wrote: > > > Could you try turning off IPQoS setting (ssh -oIPQoS=none ...) and seeing > > > whether that makes any difference? > > > > Yes - setting -oIPQoS=none on the client allows for a successful > > connection to the server. > > > > Would you still like me to check on the other things or is that enough > > to go on with? > > No - it looks like a middlebox in Amazon's network might be getting confused > when the DSCP value changes during the connection. > > Thanks a lot for helping to chase this down. > > Cheers, > Damien
On Wed, 3 Apr 2019, Adam Eijdenberg wrote:> Sigh - I think the issue may lie closer to my end. Something that I > did not mention, as it didn't seem relevant at the time, is that I'm > doing my testing from an Ubuntu running inside a VMware VM on a > Windows host. > > Now we know it's an IPQoS issue, I've found the following, suggesting > it might be a VMware networking issue: > https://communities.vmware.com/thread/597244Aah yeah, I think the VMWare problem has been discussed before.> Sorry for the noise.No worries :)