Bug 1184

Summary: remote ssh command runs very slow on windows 2003
Product: Portable OpenSSH Reporter: Shaick <shaick.pop>
Component: sshdAssignee: Assigned to nobody <unassigned-bugs>
Status: CLOSED WORKSFORME    
Severity: major CC: djm, shaick.pop
Priority: P2    
Version: 4.3p2   
Hardware: Other   
OS: Cygwin on NT/2k/Win7-11   

Description Shaick 2006-04-22 19:18:04 AEST 
I installed cygwin ( CYGWIN_NT-5.2 ) on windows 2003 and windows XP. On remote I can run the commands very fast on the XP machine. Buf from remote machine the command execution take very long to complete. Simple date command take 25 seconds to return the output. Even from the local 2003 server running command via ssh takes 20+ sec to give output.

Following is the debug output of sshd in the windows 2003 server.
2003

$ /usr/sbin/sshd -d
debug1: sshd version OpenSSH_4.3p2
debug1: private host key: #0 type 0 RSA1
debug1: read PEM private key done: type RSA
debug1: private host key: #1 type 1 RSA
debug1: read PEM private key done: type DSA
debug1: private host key: #2 type 2 DSA
debug1: rexec_argv[0]='/usr/sbin/sshd'
debug1: rexec_argv[1]='-d'
debug1: Bind to port 22 on 0.0.0.0.
Server listening on 0.0.0.0 port 22.
Generating 768 bit RSA key.
RSA key generation complete.
debug1: fd 4 clearing O_NONBLOCK
debug1: Server will not fork when running in debugging mode.
debug1: rexec start in 4 out 4 newsock 4 pipe -1 sock 7
debug1: inetd sockets after dupping: 3, 3
Connection from 130.35.185.57 port 4902
debug1: Client protocol version 2.0; client software version OpenSSH_4.3
debug1: match: OpenSSH_4.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-1.99-OpenSSH_4.3
debug1: list_hostkey_types: ssh-rsa,ssh-dss
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: kex: server->client aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST received
debug1: SSH2_MSG_KEX_DH_GEX_GROUP sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_INIT
debug1: SSH2_MSG_KEX_DH_GEX_REPLY sent
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: KEX done
debug1: userauth-request for user ntregres service ssh-connection method none
debug1: attempt 0 failures 0
Failed none for ntregres from 130.35.185.57 port 4902 ssh2
debug1: userauth-request for user ntregres service ssh-connection method publick
ey
debug1: attempt 1 failures 1
debug1: test whether pkalg/pkblob are acceptable
debug1: temporarily_use_uid: 11114/10513 (e=11114/10513)

=================HANGS about 10 secs =====================

debug1: trying public key file /home/ntregres/.ssh/authorized_keys
debug1: matching key found: file /home/ntregres/.ssh/authorized_keys, line 1
Found matching RSA key: 35:32:64:ef:b0:fe:52:6a:82:3d:1b:a6:a5:8e:96:39
debug1: restore_uid: 11114/10513
Postponed publickey for ntregres from 130.35.185.57 port 4902 ssh2
debug1: userauth-request for user ntregres service ssh-connection method publick
ey
debug1: attempt 2 failures 1
debug1: temporarily_use_uid: 11114/10513 (e=11114/10513)
debug1: trying public key file /home/ntregres/.ssh/authorized_keys
debug1: matching key found: file /home/ntregres/.ssh/authorized_keys, line 1
Found matching RSA key: 35:32:64:ef:b0:fe:52:6a:82:3d:1b:a6:a5:8e:96:39
debug1: restore_uid: 11114/10513
debug1: ssh_rsa_verify: signature correct
Accepted publickey for ntregres from 130.35.185.57 port 4902 ssh2
debug1: monitor_child_preauth: ntregres has been authenticated by privileged pro
cess
debug1: Entering interactive session for SSH2.
debug1: server_init_dispatch_20
debug1: server_input_channel_open: ctype session rchan 0 win 131072 max 32768
debug1: input_session_request
debug1: channel 0: new [server-session]
debug1: session_new: init
debug1: session_new: session 0
debug1: session_open: channel 0
debug1: session_open: session 0: link with channel 0
debug1: server_input_channel_open: confirm session
debug1: server_input_channel_req: channel 0 request exec reply 0
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 req exec

=================HANGS about 10 secs =====================


debug1: Received SIGCHLD.
debug1: session_by_pid: pid 2652
debug1: session_exit_message: session 0 channel 0 pid 2652
debug1: session_exit_message: release channel 0
debug1: session_by_channel: session 0 channel 0
debug1: session_close_by_channel: channel 0 child 0
debug1: session_close: session 0 pid 0
debug1: channel 0: free: server-session, nchannels 1
Connection closed by 130.35.185.57
debug1: do_cleanup
Closing connection to 130.35.185.57
Comment 1 Darren Tucker 2006-04-22 20:16:24 AEST 
Delays like that are often caused by DNS reverse-resolution problems.  Does adding "UseDNS no" to sshd_config (and restarting sshd) and/or putting the client's IP address in the hosts file make any difference?
Comment 2 Darren Tucker 2006-04-23 16:41:09 AEST 
*** Bug 1185 has been marked as a duplicate of this bug. ***
Comment 3 Shaick 2006-04-23 19:22:20 AEST 
With some more analysis this happens only for a domain user. For the windows 2003 localuser the SSH commands runs faster.

But I can login without any delay in terminals. Is there any way to solve this.

I added "UseDNS no" to sshd_config and IP in /etc/hosts file, but it issue exist for the domain user.
Comment 4 Damien Miller 2008-06-13 13:27:29 AEST 
Can you reproduce this with a more recent OpenSSH version (5.0p1) and corresponding cygwin DLL?
Comment 5 Shaick 2008-06-13 16:00:06 AEST 
I don't have environment to test this.
Comment 6 Damien Miller 2009-08-18 06:38:02 AEST 
Can't reproduce - probably a Cygwin issue.
Comment 7 Damien Miller 2009-10-06 15:02:58 AEDT 
Mass move of RESOLVED bugs to CLOSED now that 5.3 is out.