1.服务器端环境准备
yum update
chkconfig iptables off
chkconfig ip6tables off
vi /etc/sysconfig/selinux
SELINUX=disabled
rpm -i http://mirrors.ustc.edu.cn/fedora/epel/6/x86_64/epel-release-6-7.noarch.rpm 
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-*
2.软件安装
yum install nagios nagios-plugins nagios-plugins-all nagios-plugins-nrpe php php-pear mod_ssl net-snmp net-snmp-utils sendmail
htpasswd /etc/nagios/passwd nagiosadmin
nagios -v /etc/nagios/nagios.cfg
usermod -a -G nagios apache
chkconfig nagios on
chkconfig httpd on
chkconfig sendmail on
service sendmail restart
service httpd restart

3.配置

vim /etc/nagios/nagios.cfg
cfg_dir= /etc/nagios/servers
vim /etc/nagios/objects/commands.cfg
define command{
command_name check_nrpe
command_line /usr/lib64/nagios/plugins/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
}
mkdir /etc/nagios/servers
chown root:nagios /etc/nagios/servers
service nagios restart

4.客户端软件安装

yum install nagios-plugins-nrpe nagios-plugins-all nagios-nrpe openssl

5.监控路由器

cisco2811(config)# snmp-server community gnet RO
cisco2811(config)# snmp-server host 192.168.0.7 gnet
cisco2811(config)# snmp-server enable traps

添加监控路由器的nagios端配置文件
efine host{
        use             generic-switch          ; Inherit default values from a template
        host_name       cisco2811               ; The name we're giving to this switch
        alias           cisco2811       ; A longer name associated with the switch
        address         192.168.1.1             ; IP address of the switch
        hostgroups      routers         ; Host groups this switch is associated with
        }
define hostgroup{
        hostgroup_name  routers         ; The name of the hostgroup
        alias           Network router  ; Long name of the group
        }
define service{
        use                     generic-service ; Inherit values from a template
        host_name               cisco2811       ; The name of the host the service is associated with
        service_description     PING            ; The service description
        check_command           check_ping!200.0,20%!600.0,60%  ; The command used to monitor the service
 normal_check_interval   5               ; Check the service every 5 minutes under normal conditions
        retry_check_interval    1               ; Re-check the service every minute until its final/hard state is determined
        }

define service{
        use                     generic-service ; Inherit values from a template
        host_name               cisco2811
        service_description     Uptime
        check_command           check_snmp_time! -C gnet -o sysUpTime.0
        }



# Monitor Port 1 status via SNMP

define service{
        use                     generic-service ; Inherit values from a template
        host_name               cisco2811
        service_description     Port 1 Link Status
 check_command           check_snmp_time! -C gnet -o ifOperStatus.1 -r 1 -m RFC1213-MIB
        }

define service{
use                                             generic-service
host_name                               cisco2811
service_description                     CPU
is_volatile                                     0
check_period                            24x7
max_check_attempts                      3
retry_check_interval                    1
contact_groups                          admins
notification_interval                   120
notification_period                     24x7
check_command                           check_cisco_cpu!gnet!60!69!70!80
}

6被监控端nrpe配置

yum install nagios-plugins-nrpe nagios-plugins-all nagios-nrpe openssl
vim /etc/nagios/nrpe.cfg
allowed_hosts=127.0.0.1,192.168.0.7
chown nrpe:nrpe /etc/nagios/nrpe.cfg
vim /etc/services
nrpe            5666/tcp                # NRPE
chkconfig nrpe on