I am experiencing slow ssh login from a machine to a remote machine. The verbose of ssh is shown below in two broken blocks. ssh freezes for 15 seconds in the below shown block.
[root@zabbix ~]# ssh -vvv firstname.lastname@example.org OpenSSH_5.3p1, OpenSSL 1.0.0-fips 29 Mar 2010 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to 172.18.xxx.xx [172.18.xxx.xx] port 22. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/identity type -1 debug1: identity file /root/.ssh/id_rsa type -1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: Remote protocol version 2.0, remote software version Sun_SSH_1.1.4 debug1: no match: Sun_SSH_1.1.4 debug1: Enabling compatibility mode for protocol 2.0 ............... ............... debug1: Trying private key: /root/.ssh/id_dsa debug3: no such identity: /root/.ssh/id_dsa debug2: we did not send a packet, disable method debug3: authmethod_lookup keyboard-interactive debug3: remaining preferred: password debug3: authmethod_is_enabled keyboard-interactive debug1: Next authentication method: keyboard-interactive debug2: userauth_kbdint debug2: we sent a keyboard-interactive packet, wait for reply debug3: Wrote 96 bytes for a total of 1205
ssh hangs here for approx 15 seconds and then it asks for the password
debug2: input_userauth_info_req debug2: input_userauth_info_req: num_prompts 1 Password:
After password input, it hangs at the end of the line shown below:
debug3: packet_send2: adding 32 (len 23 padlen 9 extra_pad 64) debug3: Wrote 80 bytes for a total of 1285 debug1: Authentication succeeded (keyboard-interactive). debug1: channel 0: new [client-session] debug3: ssh_session2_open: channel_new: 0 debug2: channel 0: send open debug1: Entering interactive session. debug3: Wrote 64 bytes for a total of 1349
After approx 15 seconds, login is done successfully.
My question is, what can I do to make this ssh attempt faster?
This login attempt is done from a RHEL 6.2 machine to a Solaris 10 machine. At the very first moment I thought that it could be a network issue but later I found that I could login without any such freezes from an another Solaris 10 machine to the same remote Solaris machine I mentioned above.
The version of SSH in the remote Solaris machine is shown below:
$ ssh -V Sun_SSH_1.1.4, SSH protocols 1.5/2.0, OpenSSL 0x0090704f
While the version of SSH in RHEL machine is shown below:
[root@zabbix ~]# ssh -V OpenSSH_5.3p1, OpenSSL 1.0.0-fips 29 Mar 2010
Please note that the remote Solaris 10 machine is a zone on Physical solaris 10 machine. Attempt to login using ssh to the Physical solaris 10 machine is very fast from the local RHEL machine. So, I suppose, this is not network issue at all.
Update: Adding below all enabled directives in sshd_config file in the remote Solaris 10 machine.
Protocol 2 Port 22 ListenAddress 0.0.0.0 AllowTcpForwarding yes GatewayPorts yes X11Forwarding yes X11DisplayOffset 10 X11UseLocalhost yes PrintMotd no KeepAlive yes SyslogFacility auth LogLevel info HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key ServerKeyBits 768 KeyRegenerationInterval 3600 StrictModes yes LoginGraceTime 600 MaxAuthTries 6 MaxAuthTriesLog 3 PermitEmptyPasswords no PasswordAuthentication yes PAMAuthenticationViaKBDInt yes Subsystem sftp internal-sftp IgnoreRhosts yes RhostsAuthentication no RhostsRSAAuthentication no RSAAuthentication yes
Your input is highly appreciated.