Arch Linux

Spartan247

Member

Registered: 2020-02-18

Posts: 6

SSH working but SFTP intermitten

I've seen similar issues with SFTP on forums around, and usually their issue is extra stuff printing or running that interferes with sftp. As far as I can tell I don't see anything like that in the bashrc on my server. Sftp usually works for a bit, and then stops working, for example if I'm uploading a file it'll just freeze, and then it can't connect again after that, but ssh still works. Here's some of the verbose output of trying to connect after it stops working (started after authentication as ip address is visible in output):

debug2: fd 4 setting O_NONBLOCK
debug3: fd 5 is O_NONBLOCK
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug3: send packet: type 90
debug1: Requesting no-more-sessions@openssh.com
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: network
debug3: receive packet: type 80
debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
debug3: receive packet: type 4
debug1: Remote: /home/ryan/.ssh/authorized_keys:2: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
debug3: receive packet: type 4
debug1: Remote: /home/ryan/.ssh/authorized_keys:2: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
debug3: receive packet: type 91
debug2: channel_input_open_confirmation: channel 0: callback start
debug2: fd 3 setting TCP_NODELAY
debug3: ssh_packet_set_tos: set IP_TOS 0x20
debug2: client_session2_setup: id 0
debug1: Sending subsystem: sftp
debug2: channel 0: request subsystem confirm 1
debug3: send packet: type 98
debug2: channel_input_open_confirmation: channel 0: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768

I've seen others use

 ssh user@address /bin/true 

to test if there's any output that could interfere with sftp, and there was no output.

Zod

Member

From: Hoosiertucky

Registered: 2019-03-10

Posts: 636

Re: SSH working but SFTP intermitten

You should probably investigate maximum transmission unit or MTU.