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How to change port and enable log OpenSSH SSH daemon
published: 07 Jun 2009, in category: , , ,

The syslog-ng application is a flexible and highly scalable system logging application that is ideal for creating centralized logging solutions. The main features of syslog-ng are; reliable log transfer, secure logging using SSL/TLS, IPv4 and IPv6 support and many others” (Syslog-ng, 2008).

Problem:

On Linux Suse enterprise version, log ssh saved into /var/log/messages , or opensuse 11 like my machine doesn’t noticed into /var/log/messages. So we have a solution, what is solution ??

Solution:

we can add option log on syslog-ng and noticed into self directori or self file. example: sshderr.log for error access and sshd.log for enable access into directori /var/log/sshd.

Prepare:

1. Make sure syslog-ng have been installed on your machine.

# rpm -qa | grep syslog
syslog-ng-1.6.12-76.2

if nothing of results, you can install by yast:

# yast2 -i syslog-ng

2. Make sure openssh daemon is running

# ps aux | grep sshd

if not running, assumed we use opensuse 11 type,:

/etc/init.d/sshd start

3. Make sure enable SyslogFacility on /etc/ssh/sshd_config

SyslogFacility AUTH

Configuration:

1. Create directory /var/log/sshd

# mkdir /var/log/sshd

2. create two empty files into directori /var/log/sshd

# touch /var/log/sshd/sshderr.log
# touch /var/log/sshd/sshd.log

3. add some option into /etc/syslog-ng/syslog-ng.cnf

# SSH Filters
filter f_sshderr    { match('^sshd\[[0-9]+\]: error:'); };
filter f_sshd       { match('^sshd\[[0-9]+\]:'); };
# SSH Logging
destination sshderr { file("/var/log/sshd/sshderr.log"); };
log { source(src); filter(f_sshderr); destination(sshderr); flags(final); };
destination sshd { file("/var/log/sshd/sshd.log"); };
log { source(src); filter(f_sshd); destination(sshd); flags(final); };

4. Restart service

Suseconfig service:

# SuSEconfig
Starting SuSEconfig, the SuSE Configuration Tool...
Running in full featured mode.
Reading /etc/sysconfig and updating the system...
Executing /sbin/conf.d/SuSEconfig.glib2...
[Default Applications]
application/x-redhat-package-manager=package-manager.desktop
application/x-rpm=package-manager.desktop
Executing /sbin/conf.d/SuSEconfig.groff...
Executing /sbin/conf.d/SuSEconfig.permissions...
Finished.

Syslog-ng service:

# service syslog restart
Shutting down syslog services                                         done
Starting syslog services                                              done

done. finish.

now u can test by remote machine with ssh. try make error and repeat remote that make accessable. see ssh log:

error log:

# cat /var/log/sshd/sshderr.log
Jun  1 06:34:37 dhanuxe sshd 1579: error: PAM: Authentication failure for deanet from 125.208.155.134

accessable log:

dhanuxe:/home/deanet # cat /var/log/sshd/sshd.log
Jun  1 06:34:35 dhanuxe sshd 1579: reverse mapping checking getaddrinfo for 125.208.155.134.cbn.net.id [125.208.155.134] failed - POSSIBLE BREAK-IN ATTEMPT!

Jun 1 06:34:44 dhanuxe sshd 1579: Accepted keyboard-interactive/pam for deanet from 125.208.155.134 port 1996 ssh2

Change Port

To change ssh service you can edit following file /etc/ssh/sshd_config

Port 22

gud lak ;)

Reference:

  1. forum.opensuse.org
  2. novell.com