rsyslog Server Installation and Configuration In RHEL 7 and Centos 7

rsyslog server is used to collaborate all server logs to centralized place. System administrator no need to login each and every device to collect logs, just install and configure rsyslog server and watch all server logs using single command. Linux labels (auth, cron, ftp, lpr, authpriv, news, mail, syslog, etc ,..) the log messages to indicate the type of software that generated the messages with severity (Alert, critical, Warning, Notice, info, etc ,..).

What is syslog server

In computing,  syslog is a standard for message logging. It permits separation of the software that generates messages, the system that stores them, and the software that reports and analyzes them. Each message is labeled with a facility code, indicating the software type generating the message, and assigned a severity label.

Required Hardware and Software

rsyslog server should have at-least 4GB of RAM. 2CPU cores. 1Giga byte Network card. Installed with RHEL 7 (Red Hat Enterprise Linux 7, 7.1, 7.2 OR Centos 7).

Server Profile

  •  Packages: rsyslog*
  • Service / Daemon Name: rsyslog.service
  • Port number: 514
  • Config File: /etc/rsyslog.conf

In this article we are using Server IP:   Client IP: for demonstrate

rsyslog Server side configuration

[root@server ~]# hostname

Installing rsyslog packages

[root@server yum.repos.d]# yum install rsyslog*

Dependency Installed:
 librelp.x86_64 0:1.2.0-3.el7 postgresql-libs.x86_64 0:9.2.7-1.el7


Enable and start the services

We have to enable the service first because whenever you restart the rsyslog server it should automatically start after the reboot. If you did not enable the service it will not start we have to start service manually.

[root@server ~]# systemctl enable rsyslog.service
[root@server ~]# systemctl start rsyslog.service
[root@server ~]# systemctl status rsyslog.service

Edit config file 

Before enabling the config

[root@server ~]# vi /etc/rsyslog.conf
# rsyslog configuration file

# Provides UDP syslog reception
#$ModLoad imudp
#$UDPServerRun 514

# Provides TCP syslog reception
#$ModLoad imtcp
#$InputTCPServerRun 514

After the Change

# Provides UDP syslog reception
$ModLoad imudp
$UDPServerRun 514

# Provides TCP syslog reception
$ModLoad imtcp
$InputTCPServerRun 514

:wq! (Save & Exit)

Restart the service to effect the change

[root@server ~]# systemctl restart rsyslog.service

Allow firewall ports from server

Default port number for syslog is 514

[root@server ~]# firewall-cmd --permanent --add-port=514/tcp
[root@server ~]# firewall-cmd --permanent --add-port=514/udp
[root@server ~]# firewall-cmd --reload

Verify Service is listening

[root@server ~]# netstat -antup | grep 514

Client Side

ping to server and verify server is reachable from client

[root@desktop ~]# hostname

[root@desktop ~]# ping
PING ( 56(84) bytes of data.
64 bytes from icmp_seq=1 ttl=64 time=0.481 ms

Edit the config file

[root@desktop ~]# vi /etc/rsyslog.conf

*.* @@

:wq! (Save & Exit)

As shown above we have to point the client to send logs. . means all the logs. if would like to specify only particular logs then do not specify . in client config.

# Log anything (except mail) of level info or higher.
# Don't log private authentication messages!
*.info;mail.none;authpriv.none;cron.none /var/log/messages

# The authpriv file has restricted access.
authpriv.* /var/log/secure

# Log all the mail messages in one place.
mail.* -/var/log/maillog

# Log cron stuff
cron.* /var/log/cron

# Everybody gets emergency messages
*.emerg :omusrmsg:*

# Save news errors of level crit and higher in a special file.
uucp,news.crit /var/log/spooler

Restart the service

[root@desktop ~]# systemctl restart rsyslog.service
[root@desktop ~]# systemctl status rsyslog.service

Test logs

open log file in server and switch the users in client machine

[root@server log]# tail -f /var/log/secure
Apr 23 16:16:02 desktop su: pam_unix(su-l:session): session closed for user atkit

That’s about rsyslog server configuration.

Please provide your valuable feedback on the same

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Thanks for your wonderful Support and Encouragement

Ravi Kumar Ankam

My Name is ARK. Expert in grasping any new technology, Interested in Sharing the knowledge. Learn more & Earn More

2 Responses

  1. pugazhendhi.R says:

    Hi, Thanks for sharing this, can you please help us for the following concern: I have enabled the remote logging in firewall, switch, router but unable to customize them to their hostname separated directory.

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