I run in to it consistently when I start up our ftp server with vsftpd&. Always wondered if & had something to do with it.
-----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Mauro Souza Sent: Tuesday, April 24, 2012 8:53 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: SSH don't close session on logout I tried to disable TCPKeepAlive, and got exactly the same results... And I had nothing running on the box: I've restarted it, connected thru ssh, and exited. And It hangs that 20 seconds like before. I did some research about ClientAliveInterval, and it looks unrelated. It sends a keep-alive packet to client, so any firewall/packet filter on the way will not flag the connection as stale and kill it. And when the client does not respond to enough keep-alives, server can drop the connection. I left the client today, and I will only be back next week. I intend to try a ptrace/ltrace/strace logout, write to some file, and investigate... Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. Em 24 de abril de 2012 19:06, Pedro Principeza <pedro...@br.ibm.com>escreveu: > Mauro, > > Maybe ClientAliveInterval parameter on sshd_config can help you out with > that, I believe. > > HTH. > > Regards, > Pedro Principeza > > > > From: Richard Troth <ri...@velocitysoftware.com> > To: LINUX-390@vm.marist.edu, > Date: 24/04/2012 18:56 > Subject: Re: SSH don't close session on logout > Sent by: Linux on 390 Port <LINUX-390@vm.marist.edu> > > > > I run into this all the time. But I can't tell from your config and > description if it is exactly the same. > > What programs did you run (or what services did you start) before exiting? > > I don't suspect the TCPKeepALive. (Since you're trying to drop back > to the intermediate host.) > More likely, something is holding a file descriptor open on the remote > end. Could be "stdout" from a background process, for example. (This > is what I get: a background process or helper program continues to > run.) > > I hope this helps. > > -- R; > Rick Troth > Velocity Software > http://www.velocitysoftware.com/ > > > On Tue, Apr 24, 2012 at 4:55 PM, Mauro Souza <thoriu...@gmail.com> wrote: > > Hi guys! > > > > I've got a strange unseen problem on a sles11 sp2 today, and even Google > > couldn't help me. I connect to the machine, but when I issue an exit, > ssh > > does not closes the connection. I have to connect to a gateway machine > > before I can connect to the guest: > > > > me ----> linuxgw -----> strange_ssh > > > > But as soon as I execute an 'exit' or a 'logout' or ^D, the screen > hangs. > > It hangs the microsecond I press enter. I have to use the '~.' escape > > sequence to close the now dead connection from strange_ssh and return to > > linuxgw. > > > > I started two connections to see if the exit is being processed, and it > is: > > > > Before the exit: > > strange_ssh:~ # w > > 17:48:03 up 4 min, 2 users, load average: 0.00, 0.00, 0.00 > > USER TTY LOGIN@ IDLE JCPU PCPU WHAT > > root pts/1 17:44 35.00s 0.05s 0.05s -bash > > root pts/2 17:47 0.00s 0.03s 0.00s w > > > > Then I issue an exit, and the term hangs: > > > > strange_ssh:~ # w > > 17:48:48 up 4 min, 1 user, load average: 0.00, 0.00, 0.00 > > USER TTY LOGIN@ IDLE JCPU PCPU WHAT > > root pts/2 17:47 0.00s 0.03s 0.00s w > > > > pts/1 is killed, but my terminal shows this (and is dead): > > strange_ssh:/etc/ssh # exit > > > > Some 20 seconds later, I see a logout, and the message saying that I has > > been disconnected. > > > > The question is: how to change this 20 second timeout to something > faster, > > as I always see everywhere? > > > > This is my sshd_config file (almost all default, I only changed UseDNS > and > > TCPKeepALive): > > Protocol 2 > > PasswordAuthentication no > > GSSAPIAuthentication no > > UsePAM yes > > AllowTcpForwarding yes > > X11Forwarding yes > > TCPKeepAlive yes > > UseDNS no > > Subsystem sftp /usr/lib64/ssh/sftp-server > > AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY > > LC_MESSAGES > > AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT > > AcceptEnv LC_IDENTIFICATION LC_ALL > > > > > > Thanks! > > > > Mauro > > http://mauro.limeiratem.com - registered Linux User: 294521 > > Scripture is both history, and a love letter from God. > > > > ---------------------------------------------------------------------- > > For LINUX-390 subscribe / signoff / archive access instructions, > > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > visit > > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > ---------------------------------------------------------------------- > > For more information on Linux on System z, visit > > http://wiki.linuxvm.org/ > > > > -- > -- R; > Rick Troth > Velocity Software > http://www.velocitysoftware.com/ > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > > > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/ ----------------------------------------------------- Please see the following link for the BlueCross BlueShield of Tennessee E-mail disclaimer: http://www.bcbst.com/email_disclaimer.shtm ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
