I've started running into a problem with outbound SSH connections from a linux guest being dropped as soon as connection is established. The issue is repeatable and fixable with a kludge that modifies QoS.
The issue manifests itself by dropping the connection immediately after establishing it:
$ ssh $host
packet_write_wait: Connection to $host port 22: Broken pipe
Enabling verbose flags (-v or -vvv) doesn't show anything remarkable.
I've been in contact with my linux distribution's maintainers[1] and they have helped narrow the problem down to an issue with vmnat misbehaving.
Because vmnat do not recognise AF21/CS1 DSCP flags, it'll send back a RST packet (don't know why) immediately upon received any packet having either flags, and finally break all ssh connection. (This happens soon after authentication since IPQoS applies during channel establish) [2]
This is on VMWare Workstation 12 Player, version 12.5.9 build-7535481, running on Win 7 Enterprise. My guest is running a current Linux kernel (4.9.95) and openssh 7.7_p1-r4 (though it seems like any software that uses QoS will have this problem.)
Setting alternate QoS flags seems to work around the issue, e.g. ssh -o IPQoS=throughput ...
References:
Thanks for sharing this solution...I was going nuts trying to figure out what was happening 😕
Great. Thank you! You saved my day!
Thanks for sharing that, been trying to fix this issue on my Macbook for weeks now!
I met the same problem: linux - From VMware and Fedora 29 ssh to remote machine cause Broken pipe - Super User
Meanwhile, scp command also have to add -o 'IPQoS=throughput'.
Thanks, that helped a lot!
Setting IPQoS=throughput in ~/.ssh/config fixes it for all programs using ssh, as far as I can tell (for example, git).
I have also been having this problem for a while. What's peculiar is that it only affects an ssh session from my MacBook Pro laptop (when I am home) connecting to my work iMac
I am running Mojave 10.14.3 on both ends
My only recourse right now is doing an ssh into a lab VM, then ssh into my iMac, which feels really weird !
Thanks,
Reza