Hi all, I've finally figured this one out. After sniffing some traffic I found that, even with "UseDNS no", the sshd was still performing DNS queries. For some reason in this newer version it was performing an ipv6 (AAAA) query first, which the DNS server seems to be silently discarding rather than replying with an NXDOMAIN. As a workaround I edited /etc/netsvc.conf from "hosts = local, bind" to "hosts = local, bind4" Thanks to everyone who replied and helped with this issue. Regards, David David R Green <dgreen49@xxxxxxxxxx> Sent by: listbounce@xxxxxxxxxxxxxxxxx 24/06/2008 03:36 PM To Georgi Stanojevski <glisha@xxxxxxxxx> cc secureshell@xxxxxxxxxxxxxxxxx Subject Re: ssh connection pause Hi Georgi, I provided the output of that in my original post: >From the client: --- dgreen49@linuxhost1 [~]# ssh -vvv aixhost1 OpenSSH_4.3p2-hpn, OpenSSL 0.9.7a Feb 19 2003 debug1: Reading configuration data /opt/soe/local/etc/ssh_config debug2: ssh_connect: needpriv 0 debug1: Connecting to 10.44.138.107 [10.44.138.107] port 22. debug1: Connection established. debug1: identity file /home/dgreen49/.ssh/identity type -1 debug1: identity file /home/dgreen49/.ssh/id_rsa type -1 debug1: identity file /home/dgreen49/.ssh/id_dsa type -1 <pauses here> debug1: Remote protocol version 2.0, remote software version OpenSSH_4.6p1-hpn12v17 debug1: match: OpenSSH_4.6p1-hpn12v17 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_4.3p2-hpn debug2: fd 3 setting O_NONBLOCK [...] --- >From the server: --- root@aixhost1 [~]# /opt/soe/local/openssh/sbin/sshd -ddd [...] debug1: rexec_argv[0]='/opt/soe/local/openssh/sbin/sshd' debug1: rexec_argv[1]='-ddd' debug2: fd 3 setting O_NONBLOCK debug1: Bind to port 22 on 0.0.0.0. debug1: Server TCP RWIN socket size: 65536 debug1: HPN Buffer Size: 131072 Server listening on 0.0.0.0 port 22. debug1: fd 4 clearing O_NONBLOCK debug1: Server will not fork when running in debugging mode. debug3: send_rexec_state: entering fd = 7 config len 1421 debug3: ssh_msg_send: type 0 debug3: send_rexec_state: done debug1: rexec start in 4 out 4 newsock 4 pipe -1 sock 7 <pauses here> debug1: inetd sockets after dupping: 3, 3 Connection from linuxhost1 port 1119 [...] --- Regards, David Georgi Stanojevski <glisha@xxxxxxxxx> wrote on 24/06/2008 03:32:28 PM: > David R Green wrote: > > > I should mention that these AIX servers were successfully running openssh > > 4.5. It's only since the upgrade to 4.6 that the connection pause occurs. > > Run the ssh client in verbose mode (ex. ssh -vv user@host) and see where > does the pause happen. > > -- > Glisha
