在Nagios中配置使用SNMP来监控网络设备，可以按照以下步骤进行：
1、安装SNMP相关软件包
对于基于Debian的系统（如Ubuntu），可以使用以下命令安装SNMP相关软件包：
“`
sudo aptget install snmp snmpd libsnmpdev
“`
对于基于RPM的系统（如CentOS、Red Hat），可以使用以下命令安装SNMP相关软件包：
“`
sudo yum install netsnmp netsnmputils netsnmplibs
“`
2、配置SNMP代理（SNMP Daemon）
编辑SNMP代理配置文件/etc/snmp/snmpd.conf，添加以下内容：
“`
community public <监控设备团体名>
view systemview included .iso.org.dod.internet.private.enterprises.9.1.1
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
access notConfigGroup "" any noauth exact all none view all none
“`
将<aclpublic替换为监控设备的团体名，如果监控设备的团体名为mycommunity，则应将其替换为mycommunity。
保存并关闭配置文件。
重启SNMP代理服务以应用更改：
“`
sudo systemctl restart snmpd
“`
3、在Nagios中创建主机和监控项定义文件（可选）
在Nagios配置文件目录（默认为/etc/nagios3/objects）下创建主机定义文件（myhost.cfg），该文件包含主机的基本信息和监控项的定义，示例内容如下：
“`ini
# myhost.cfg Nagios host definition file for monitoring network devices using SNMP.
define host {
use generichost ; Name of host template to use (required)
host_name mydevice ; Description of the host (required)
alias My Device ; A longer name for the host (optional)
address <监控设备IP地址> ; IP address or DNS name of the host (required)
} # end define host mydevice
“`
