SSH login is failing with permission denied error in AIX 5.3 ML08

I have a AIX 5.3 ML08 server. When I try to login with SSH, both as root user and non-root user, it fails with permission denied error message.

Below is the output,
ssh -l user etr6506l3-aix93.ca.com
user@etr6506l3-aix93.ca.com's password:
Permission denied, please try again.
user@etr6506l3-aix93.ca.com's password:
Permission denied, please try again.
user@etr6506l3-aix93.ca.com's password:
Received disconnect from 155.35.7.36: 2: Too many authentication failures for user

If I look into the syslog messages file, the following PAM related error messages are observed,

May 14 07:08:01 etr6506l3-aix93 auth|security:debug sshd: PAM: pam_authenticate: error Authentication failed
May 14 07:08:01 etr6506l3-aix93 auth|security:debug sshd: PAM: pam_authenticate: error Authentication failed
May 14 07:08:01 etr6506l3-aix93 auth|security:info sshd[274440]: Failed password for user from 155.35.7.36 port 32836 ssh2
May 14 07:08:01 etr6506l3-aix93 auth|security:info sshd[274440]: Failed password for user from 155.35.7.36 port 32836 ssh2
May 14 07:08:01 etr6506l3-aix93 auth|security:info syslog: ssh: failed login attempt for user from etr6506l3-aix93.ca.com
May 14 07:08:01 etr6506l3-aix93 auth|security:info syslog: ssh: failed login attempt for user from etr6506l3-aix93.ca.com

Could you please help me out in resolving this problem.

The sshd_config file looks as below,

#       $OpenBSD: sshd_config,v 1.73 2005/12/06 22:38:28 reyk Exp $

# This is the sshd server system-wide configuration file.  See
# sshd_config(5) for more information.

# This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented.  Uncommented options change a
# default value.

#Port 22
Protocol 2
#AddressFamily any
#ListenAddress 0.0.0.0
#ListenAddress ::

# HostKey for protocol version 1
# HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key

# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 1h
#ServerKeyBits 768

# Logging
# obsoletes QuietMode and FascistLogging
SyslogFacility AUTH
#LogLevel INFO

# Authentication:

#LoginGraceTime 2m
PermitRootLogin yes
#StrictModes yes
MaxAuthTries 3

#RSAAuthentication yes
#PubkeyAuthentication yes
#AuthorizedKeysFile     .ssh/authorized_keys

# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes

# To disable tunneled clear text passwords, change to no here!
#PasswordAuthentication yes
#PermitEmptyPasswords no

# Change to no to disable s/key passwords
#ChallengeResponseAuthentication no

# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes

# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication mechanism.
# Depending on your PAM configuration, this may bypass the setting of
# PasswordAuthentication, PermitEmptyPasswords, and
# "PermitRootLogin without-password". If you just want the PAM account and
# session checks to run without PAM authentication, then enable this but set
# ChallengeResponseAuthentication=no
UsePAM yes

#AllowTcpForwarding yes
#GatewayPorts no
#X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost no
#PrintMotd yes
#PrintLastLog yes
#TCPKeepAlive yes
#UseLogin no
#UsePrivilegeSeparation yes
#PermitUserEnvironment no
#Compression delayed
#ClientAliveInterval 0
#ClientAliveCountMax 3
#UseDNS yes
#PidFile /var/run/sshd.pid
#MaxStartups 10
#PermitTunnel no

# no default banner path
Banner /some/path

# override default of no subsystems
Subsystem       sftp    /usr/sbin/sftp-server

Select allOpen in new window