25.6. Configuring rsyslog on a Logging Server The rsyslog service provides facilities both for running a logging server and for configuring individual systems to send their log files to the logging server. See Example 25.12, "Reliable Forwarding of Log Messages to a Server" for information on client rsyslog configuration. The rsyslog service must be installed on the system that you intend to use as a logging server and all systems that will be configured to send logs to it. Rsyslog is installed by default in Red Hat Enterprise Linux 6. If required, to ensure that it is, enter the following command as root : The default protocol and port for syslog traffic is UDP and 514 , as listed in the /etc/services file. However, rsyslog defaults to using TCP on port 514 . In the configuration file, /etc/rsyslog.conf , TCP is indicated by @@ . Other ports are sometimes used in examples, however SELinux is only configured to allow sending and receiving on the following ports by default: The semanage utility is provided as part of the policycoreutils-python package. If required, install the package as follows: In addition, by default the SELinux type for rsyslog , rsyslogd_t , is configured to permit sending and receiving to the remote shell ( rsh ) port with SELinux type rsh_port_t , which defaults to TCP on port 514 . Therefore it is not necessary to use semanage to explicitly permit TCP on port 514 . For example, to check what SELinux is set to permit on port 514 , enter a command as follows: For more information on SELinux, see Red Hat Enterprise Linux 6 SELinux User Guide . Perform the steps in the following procedures on the system that you intend to use as your logging server. All steps in these procedure must be made as the root user. Procedure 25.5. Configure SELinux to Permit rsyslog Traffic on a Port If required to use a new port for rsyslog traffic, follow this procedure on the logging server and the clients. For example, to send and receive TCP traffic on port 10514 , proceed as follows: Review the SELinux ports by entering the following command: If the new port was already configured in /etc/rsyslog.conf , restart rsyslog now for the change to take effect: Verify which ports rsyslog is now listening to: See the semanage-port(8) manual page for more information on the semanage port command. Procedure 25.6. Configuring The iptables Firewall Configure the iptables firewall to allow incoming rsyslog traffic. For example, to allow TCP traffic on port 10514 , proceed as follows: Open the /etc/sysconfig/iptables file in a text editor. Add an INPUT rule allowing TCP traffic on port 10514 to the file. The new rule must appear before any INPUT rules that REJECT traffic. Save the changes to the /etc/sysconfig/iptables file. Restart the iptables service for the firewall changes to take effect. Procedure 25.7. Configuring rsyslog to Receive and Sort Remote Log Messages Open the /etc/rsyslog.conf file in a text editor and proceed as follows: Add these lines below the modules section but above the Provides UDP syslog reception section: Replace the default Provides TCP syslog reception section with the following: Save the changes to the /etc/rsyslog.conf file. The rsyslog service must be running on both the logging server and the systems attempting to log to it. Use the service command to start the rsyslog service. To ensure the rsyslog service starts automatically in future, enter the following command as root: Your log server is now configured to receive and store log files from the other systems in your environment. 25.6.1. Using The New Template Syntax on a Logging Server Rsyslog 7 has a number of different templates styles. The string template most closely resembles the legacy format. Reproducing the templates from the example above using the string format would look as follows: These templates can also be written in the list format as follows: This template text format might be easier to read for those new to rsyslog and therefore can be easier to adapt as requirements change. To complete the change to the new syntax, we need to reproduce the module load command, add a rule set, and then bind the rule set to the protocol, port, and ruleset:

Commands:
~]# yum install rsyslog
~]# semanage port -l | grep syslog syslogd_port_t tcp 6514, 601 syslogd_port_t udp 514, 6514, 601
~]# yum install policycoreutils-python
~]# semanage port -l | grep 514 output omitted rsh_port_t tcp 514 syslogd_port_t tcp 6514, 601 syslogd_port_t udp 514, 6514, 601
~]# semanage port -a -t syslogd_port_t -p tcp 10514
~]# semanage port -l | grep syslog
~]# service rsyslog restart
~]# netstat -tnlp | grep rsyslog tcp 0 0 0.0.0.0: 10514 0.0.0.0:* LISTEN 2528/rsyslogd tcp 0 0 :::10514 :::* LISTEN 2528/rsyslogd
-A INPUT -m state --state NEW -m tcp -p tcp --dport 10514 -j ACCEPT
~]# service iptables restart
Define templates before the rules that use them ### Per-Host Templates for Remote Systems ### USDtemplate TmplAuthpriv, "/var/log/remote/auth/%HOSTNAME%/%PROGRAMNAME:::secpath-replace%.log" USDtemplate TmplMsg, "/var/log/remote/msg/%HOSTNAME%/%PROGRAMNAME:::secpath-replace%.log"
Provides TCP syslog reception USDModLoad imtcp Adding this ruleset to process remote messages USDRuleSet remote1 authpriv.* ?TmplAuthpriv *.info;mail.none;authpriv.none;cron.none ?TmplMsg USDRuleSet RSYSLOG_DefaultRuleset #End the rule set by switching back to the default rule set USDInputTCPServerBindRuleset remote1 #Define a new input and bind it to the "remote1" rule set USDInputTCPServerRun 10514
~]# service rsyslog start
~]# chkconfig rsyslog on
template(name="TmplAuthpriv" type="string" string="/var/log/remote/auth/%HOSTNAME%/%PROGRAMNAME:::secpath-replace%.log" ) template(name="TmplMsg" type="string" string="/var/log/remote/msg/%HOSTNAME%/%PROGRAMNAME:::secpath-replace%.log" )
template(name="TmplAuthpriv" type="list") { constant(value="/var/log/remote/auth/") property(name="hostname") constant(value="/") property(name="programname" SecurePath="replace") constant(value=".log") } template(name="TmplMsg" type="list") { constant(value="/var/log/remote/msg/") property(name="hostname") constant(value="/") property(name="programname" SecurePath="replace") constant(value=".log") }
module(load="imtcp") ruleset(name="remote1"){ authpriv.* action(type="omfile" DynaFile="TmplAuthpriv") *.info;mail.none;authpriv.none;cron.none action(type="omfile" DynaFile="TmplMsg") } input(type="imtcp" port="10514" ruleset="remote1")