引言
想对某些网络设备（路由器、交换机等）进行监控时，其不支持安装监控 Agent ，但一般都支持 SNMP 方式的监控。
所以现在来重新学习下 SNMP 原理与安装配置。
SNMP 简介
Simple Network Management Protocol (SNMP) is an Internet-standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically support SNMP include routers, switches, servers, workstations, printers, modem racks and more.
1 安装配置 snmp
# 1. 安装 snmp 相关包组
yum list | grep snmp
yum install net-snmp net-snmp-utils -y
# 2. 配置 snmpd.conf
[root@linux-node1 ~]# cat /etc/snmp/snmpd.conf
rocommunity jaminzhang 127.0.0.1
rocommunity jaminzhang 192.168.56.11
# 3. 启动 snmpd
[root@linux-node1 ~]# systemctl start snmpd
[root@linux-node1 ~]# netstat -lntup | grep snmp
tcp 0 0 127.0.0.1:199 0.0.0.0:* LISTEN 28604/snmpd
udp 0 0 0.0.0.0:161 0.0.0.0:* 28604/snmpd
# 4. 测试 snmp 获取数据
[root@linux-node1 ~]# snmpget -v2c -c jaminzhang 192.168.56.11 1.3.6.1.2.1.1.3.0
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (11110) 0:01:51.10
[root@linux-node1 ~]# snmpget -v2c -c jaminzhang 192.168.56.11 1.3.6.1.4.1.2021.10.1.3.1
UCD-SNMP-MIB::laLoad.1 = STRING: 0.00
[root@linux-node1 ~]# snmpwalk -v2c -c jaminzhang 192.168.56.11 1.3.6.1.4.1.2021.10.1.3
UCD-SNMP-MIB::laLoad.1 = STRING: 0.15
UCD-SNMP-MIB::laLoad.2 = STRING: 0.07
UCD-SNMP-MIB::laLoad.3 = STRING: 0.06
2 SNMP 协议概念及参考资料
Management information base (MIB) Object identifier (OID)
SNMP protocol data unit (PDU) types:
- GetRequest
- SetRequest
- GetNextRequest
- GetBulkRequest
- Response
- Trap
- InformRequest
SNMP 相关参考资料
Simple Network Management Protocol - Wiki
Simple Network Management Protocol
SNMP PDU
《Zabbix 企业级分布式监控系统》7.5 SNMP 监控方式
SNMP 常用 OID
浅谈 Linux 系统中的 SNMP Trap
配置 snmp
